# Trespassing and Undercover Investigations
**URL:** https://boards.straightdope.com/t/trespassing-and-undercover-investigations/851108
**Category:** Great Debates
**Created:** [April 5, 2020, 4:53am UTC](https://boards.straightdope.com/t/trespassing-and-undercover-investigations/851108 "2020-04-05T04:53:47Z")
**Posts on this page:** 20
**Page:** 2
### Author:  [@UltraVires](https://boards.straightdope.com/u/UltraVires)
#### Post date: [April 7, 2020, 8:43pm UTC](https://boards.straightdope.com/t/trespassing-and-undercover-investigations/851108/21 "2020-04-07T20:43:57Z")
> [@DrDeth](#):
>
> I can build a fence from scrap wood and wire, cost= zero.
>
> And no, people dont need a way to hide their meth labs from the police.
?? Unless the police have probable cause to search my house, I have ever right to hide stuff from the police, nosy neighbors, or anyone else.
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### Author:  [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)
#### Post date: [April 7, 2020, 9:35pm UTC](https://boards.straightdope.com/t/trespassing-and-undercover-investigations/851108/22 "2020-04-07T21:35:45Z")
> [@UltraVires](#):
>
> I agree, but that is not the case here. The individual would not be saying that the case law doesn’t apply to him. He would be attempting to revoke the implicit consent that was discussed in Jardines. Jardines doesn’t stand for the proposition that this implicit consent survives at all times.
IANAL but my understanding of Jardines is that it’s saying the police can enter your property as long as they are doing so for the same reasons that you allow other visitors to enter your property. In other words, if you allow people in general to walk up to your front door, you cannot create a special exemption forbidding police officers (or “snitches”) to do the same.
So I feel that if somebody put a sign up specifically saying **“No Trespassing; and I hereby explicitly revoke the implied license referred to in Jardines.”** they would be declaring that they are asserting they have the right to make special exemptions like specifically forbidding the police. The fact that they specifically refer to the Jardines decision seems to imply they are trying to claim the Jardines decision doesn’t apply to them.
To make an analogy, if a town put up a sign that said **“Speed limit 35mph; and we hereby explicitly revoke the implied limits referred to in Knowles”** I think it would be clear they were going beyond merely setting a speed limit. They appear to be declaring that if you get a speeding ticket, the police officer would be allowed to conduct a full search of your vehicle.
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### Author:  [@UltraVires](https://boards.straightdope.com/u/UltraVires)
#### Post date: [April 7, 2020, 10:15pm UTC](https://boards.straightdope.com/t/trespassing-and-undercover-investigations/851108/23 "2020-04-07T22:15:07Z")
> [@Little\_Nemo](#):
>
> IANAL but my understanding of Jardines is that it’s saying the police can enter your property as long as they are doing so for the same reasons that you allow other visitors to enter your property. In other words, if you allow people in general to walk up to your front door, you cannot create a special exemption forbidding police officers (or “snitches”) to do the same.
>
> So I feel that if somebody put a sign up specifically saying **“No Trespassing; and I hereby explicitly revoke the implied license referred to in Jardines.”** they would be declaring that they are asserting they have the right to make special exemptions like specifically forbidding the police. The fact that they specifically refer to the Jardines decision seems to imply they are trying to claim the Jardines decision doesn’t apply to them.
>
> To make an analogy, if a town put up a sign that said **“Speed limit 35mph; and we hereby explicitly revoke the implied limits referred to in Knowles”** I think it would be clear they were going beyond merely setting a speed limit. They appear to be declaring that if you get a speeding ticket, the police officer would be allowed to conduct a full search of your vehicle.
I disagree. As a property owner, I can have whatever rules I want regarding who is permitted access. I can say that Little Nemo is allowed, but that scofflaw Dr. Deth is not. Because it is purely private property, I can say that no blacks or Jews are allowed, or I can ban white males. Public accommodations laws do not apply.
What Jardines was discussing is the general law of trespass. To what extent can you or Dr. Deth enter my property absent any indication that I have disallowed your entry? And what is clear from centuries of case law is that if you come to my house, see a sidewalk and steps up to the front door, that creates an implied license to walk up, knock on the door and attempt to speak with me for normal purposes.
But nobody disputes that I am able to revoke that implied license, but to be effective I have to communicate that in some way. Placing a fence and an armed guard who tells anyone who comes (that is not on my approved list) that they are not permitted to enter, is an undisputedly effective way to do that.
My point of discussion in this thread, given that armed guards are impractical for most people, is what else acts as notification that such implied consent is revoked? And I would think that if I have expressly told Dr. Deth that if he is simply coming to my house to find criminal activity (a snitch) and he does so with the intent of being a snitch, then he has been put on notice that his implied license to come has been revoked.
This is not like your hypothetical speed limit sign. Knowles places limits on government behavior which cannot be revoked with a sign. Jardines discusses private property owners’ general expectations without further action. It does not state that those owners must always and forever extend the implied license, either to all or to any individual.
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### Author:  [@DrDeth](https://boards.straightdope.com/u/DrDeth)
#### Post date: [April 7, 2020, 10:54pm UTC](https://boards.straightdope.com/t/trespassing-and-undercover-investigations/851108/24 "2020-04-07T22:54:11Z")
> [@UltraVires](#):
>
> …
> My point of discussion in this thread, given that armed guards are impractical for most people, is what else acts as notification that such implied consent is revoked? And I would think that if I have expressly told Dr. Deth that if he is simply coming to my house to find criminal activity (a snitch) and he does so with the intent of being a snitch, then he has been put on notice that his implied license to come has been revoked…
No, just a sign doesnt do it. Generally, a HOA cant arrest solicitors, nor does a NO Soliciting sing on your property mean a salesman is trespassing.
Read this letter from the Police on that:
> **[Solicitors vs City Permits vs Trespassing Signs and No Solicitation Signs...](https://nextdoor.com/agency-post/nc/greensboro/greensboro-police-department/solicitors-vs-city-permits-vs-trespassing-signs-and-no-solicitation-signs-24485108/)**
>
> Hello Everyone,
> I see the post and comments you all have been having about this subject. You've had some great questions and some very valid concerns. I wanted to be sure you had Good and Correct information on this topic so I turned to our...
Now, in some areas, yes, just a sign will keep Solicitors out, due to local regulations. But those are special cases. And in fact, even so, they wont keep Religious Solicitors out- the Adventist or Mormons have a right to proselytize. You have a right to tell them to fuck off and go to hell, if that’s what you wish.
In Jardines, the Police brought in a special tool (a dog) which is what caused SCOTUS to burp. If the police had just seen the hemp thru a window, it would have been fine. Of course we also now know that the drug sniffing dog is worthless for probable cause as the handler can have the dog signal anytime the handler chooses.
So, it’s pretty much ALL or none, and ALL means- as has been explained- some sort of barrier,\* and \*a Sign. Neither holds water by themselves.
If you are poor or renting, perhaps you should not use your house as a meth lab. You dont have the right to use your house as a meth lab.
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### Author:  [@Melbourne](https://boards.straightdope.com/u/Melbourne)
#### Post date: [April 10, 2020, 3:53am UTC](https://boards.straightdope.com/t/trespassing-and-undercover-investigations/851108/25 "2020-04-10T03:53:32Z")
> [@UltraVires](#):
>
> And that is an excellent point. It would seem that no sign is required because although I allow solicitors to come to the front door, knock on it or ring the doorbell, and attempt to communicate with me, and I allow friends to come into my house because they are friends, this implied license does not extend to “people who are pretending to be friends but have the ultimate purpose of reporting what they see and hear to law enforcement.” Even if I invite them in, they are gaining entrance through fraud which activates the doctrine of trespass ab initio.
>
> Just as the implied license does not extend to police with a drug sniffing dog, it should equally not extend to people who are coming to my house with the intent to gather evidence in a criminal trial.
The fact is that in spite of saying clearly that you didn’t want to, you did sell the drugs in your home to a snitch. Those were actions you took, and aren’t mistakes you make in a different class to things that happen to you without your involvement?
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### Author:  [@UltraVires](https://boards.straightdope.com/u/UltraVires)
#### Post date: [April 10, 2020, 10:49am UTC](https://boards.straightdope.com/t/trespassing-and-undercover-investigations/851108/26 "2020-04-10T10:49:32Z")
> [@DrDeth](#):
>
> No, just a sign doesnt do it. Generally, a HOA cant arrest solicitors, nor does a NO Soliciting sing on your property mean a salesman is trespassing.
>
> Read this letter from the Police on that:
>
> [Solicitors vs City Permits vs Trespassing Signs and No Solicitation Signs (Greensboro Police Department) — Nextdoor — Nextdoor](https://nextdoor.com/agency-post/nc/greensboro/greensboro-police-department/solicitors-vs-city-permits-vs-trespassing-signs-and-no-solicitation-signs-24485108/)
>
> Now, in some areas, yes, just a sign will keep Solicitors out, due to local regulations. But those are special cases. And in fact, even so, they wont keep Religious Solicitors out- the Adventist or Mormons have a right to proselytize. You have a right to tell them to fuck off and go to hell, if that’s what you wish.
>
> In Jardines, the Police brought in a special tool (a dog) which is what caused SCOTUS to burp. If the police had just seen the hemp thru a window, it would have been fine. Of course we also now know that the drug sniffing dog is worthless for probable cause as the handler can have the dog signal anytime the handler chooses.
>
> So, it’s pretty much ALL or none, and ALL means- as has been explained- some sort of barrier,\* and \*a Sign. Neither holds water by themselves.
>
> If you are poor or renting, perhaps you should not use your house as a meth lab. You dont have the right to use your house as a meth lab.
Whether the police will arrest someone for trespassing does not answer the question of whether they are trespassing. Trespassing is generally a civil tort backed up in limited circumstances by criminal laws.
And again, this isn’t about a strawman right to sell drugs in my house. Everyone agrees you cannot do that. What is the legal right is the basic right of private property ownership: the right to exclude others. To stop drug selling in homes, we do what we do in a free society, we have the police get probable cause and a search warrant, not trespass onto peoples’ property to gather evidence. That applies to both poor and rich people.
And if you are on a jury and a person testifies that they saw a “No Solicitors” sign and decided “Fuck it, I am going to go solicit anyways” would you not find that they entered the property against the owner’s wishes, i.e. trespassed?
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### Author:  [@Ann\_Hedonia](https://boards.straightdope.com/u/Ann_Hedonia)
#### Post date: [April 10, 2020, 4:43pm UTC](https://boards.straightdope.com/t/trespassing-and-undercover-investigations/851108/27 "2020-04-10T16:43:38Z")
> [@UltraVires](#):
>
> To add, although my question is general, the specific facts of the case are that the defendant, in the prior six months had told all of his friends that if they were ever “snitches” they were not welcome in his home.
>
> Well, one of those people got popped and started working for the police. That person then entered his home and allegedly bought drugs from him in his home. That person will testify that the defendant stated that snitches were not welcome in his home.
>
> Consistent with current case law, did the defendant’s admonition that no “snitches” were welcome in his home give notice to that person that entry was unauthorized and make it a trespass, one directed by the state?
First, I’m hoping this is a theoretical discussion and that you don’t intend to actually go into court and make this argument in front of a judge. If you are, please send me the date, time and other details. I’d really like to see that.
First, it sounds like “he said , he said”. We have only the word of your client, and possibly his criminal associates, that your client put everyone on notice that snitches weren’t welcome in his home. That does not rise to the level of a sign. Maybe your client should’ve put up a sign on the porch that said “People that are going to rat me out to the cops for dealing drugs are not welcome on these premises.” That might hold more legal weight, but it would probably cause more problems than it solves.
Let’s say I tell my boyfriend that if he ever comes near that skank that used to be his side piece again he isn’t welcome in my home. He comes home one night, I smell her dollar store perfume on him and I shoot him. Could I make a legal argument that I shot a trespasser?
So, I don’t think a casual statement like “snitches aren’t welcome in my home” ( which should go without saying, anyway) has any force as legal notice, especially in a criminal matter.
Second, I think there might be some sort of “clean hands” doctrine that negates any legal force your argument might have. I don’t think you can require a person to agree to do something illegal, like perjure themselves to the cops, in exchange for the legal right to be on your property.
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### Author:  [@DrDeth](https://boards.straightdope.com/u/DrDeth)
#### Post date: [April 10, 2020, 4:47pm UTC](https://boards.straightdope.com/t/trespassing-and-undercover-investigations/851108/28 "2020-04-10T16:47:07Z")
> [@UltraVires](#):
>
> …
>
> And if you are on a jury and a person testifies that they saw a “No Solicitors” sign and decided “Fuck it, I am going to go solicit anyways” would you not find that they entered the property against the owner’s wishes, i.e. trespassed?
Nope. Not unless that salesperson went over a fence or some other barrier.
Look, signs like “Cops are not allowed” would be just as useful as asking a undercover narc “Are you a cop?”.
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### Author:  [@UltraVires](https://boards.straightdope.com/u/UltraVires)
#### Post date: [April 11, 2020, 7:17am UTC](https://boards.straightdope.com/t/trespassing-and-undercover-investigations/851108/29 "2020-04-11T07:17:15Z")
> [@Ann\_Hedonia](#):
>
> First, I’m hoping this is a theoretical discussion and that you don’t intend to actually go into court and make this argument in front of a judge. If you are, please send me the date, time and other details. I’d really like to see that.
>
> First, it sounds like “he said , he said”. We have only the word of your client, and possibly his criminal associates, that your client put everyone on notice that snitches weren’t welcome in his home. That does not rise to the level of a sign. Maybe your client should’ve put up a sign on the porch that said “People that are going to rat me out to the cops for dealing drugs are not welcome on these premises.” That might hold more legal weight, but it would probably cause more problems than it solves.
>
> Let’s say I tell my boyfriend that if he ever comes near that skank that used to be his side piece again he isn’t welcome in my home. He comes home one night, I smell her dollar store perfume on him and I shoot him. Could I make a legal argument that I shot a trespasser?
>
> So, I don’t think a casual statement like “snitches aren’t welcome in my home” ( which should go without saying, anyway) has any force as legal notice, especially in a criminal matter.
>
> Second, I think there might be some sort of “clean hands” doctrine that negates any legal force your argument might have. I don’t think you can require a person to agree to do something illegal, like perjure themselves to the cops, in exchange for the legal right to be on your property.
1. The snitch will testify that my client said that.
2. You cannot shoot any trespasser unless you are in reasonable fear of death or bodily harm. Your boyfriend cheating, although emotionally harmful, does not put you in fear of death or bodily harm. Although if you told him that, I would think he is trespassing. Please cite a case where you believe he is not. You gave him conditional admission to your property, he refused the condition, and entered anyways. It is not criminal trespass, but certainly civil.
3. You are not requiring a person to do something illegal in exchange for entry to your property. There is nothing illegal about not reporting a crime, especially one that they engaged in as a ruse to incriminate you. The person is free to disavow themself of the previously enjoyed privilege to enter your property. And you are right. “It goes without saying.” So why would the snitch believe that you would consent to entry upon your property for that purpose?
> [@DrDeth](#):
>
> Nope. Not unless that salesperson went over a fence or some other barrier.
>
> Look, signs like “Cops are not allowed” would be just as useful as asking a undercover narc “Are you a cop?”.
1. You are all about fences. Trespass law in tort does not require a fence. Just notice that the entry on your property is forbidden. You think a guy that got caught shoplifting at WalMart and given a trespass notice could go back and say, “But there is no fence here!”
2. Asking a person “Are you a cop?” and have them lie to you by saying “No” is not a trespass upon your “persons, papers, houses, and effects” as stated in the Fourth Amendment. A person trespassing on your property after you have given express directives that they not enter your property is a violation of that Amendment.
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### Author:  [@MikeF](https://boards.straightdope.com/u/MikeF)
#### Post date: [April 11, 2020, 12:51pm UTC](https://boards.straightdope.com/t/trespassing-and-undercover-investigations/851108/30 "2020-04-11T12:51:43Z")
Isn’t there something known as “The Judas Exception” when it comes to expectation of privacy? In other words, if you trusted someone who betrays you, too bad. You shouldn’t have trusted them.
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### Author:  [@doreen](https://boards.straightdope.com/u/doreen)
#### Post date: [April 11, 2020, 1:21pm UTC](https://boards.straightdope.com/t/trespassing-and-undercover-investigations/851108/31 "2020-04-11T13:21:10Z")
> [@UltraVires](#):
>
> 1. The snitch will testify that my client said that.
>
> 2. You cannot shoot any trespasser unless you are in reasonable fear of death or bodily harm. Your boyfriend cheating, although emotionally harmful, does not put you in fear of death or bodily harm. Although if you told him that, I would think he is trespassing. Please cite a case where you believe he is not. You gave him conditional admission to your property, he refused the condition, and entered anyways. It is not criminal trespass, but certainly civil.
Of course she can’t shoot him - but if you believe it’s civil trespass, why isn’t it criminal trespass? If telling him he’s only welcome under certain conditions is sufficient notice to make it civil trespass, why isn’t it enough for a criminal charge?
> [@](#):
>
> 1. You are all about fences. Trespass law in tort does not require a fence. Just notice that the entry on your property is forbidden. You think a guy that got caught shoplifting at WalMart and given a trespass notice could go back and say, “But there is no fence here!”
Why does Walmart (or any other place) have to issue a trespass notice to begin with? Why can’t they post a sign simply saying shoplifters aren’t permitted to enter ? And once Walmart posts such a sign, why can’t the police charge shoplifters with criminal trespass in addition to whatever charge covers the shoplifting?
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### Author:  [@DrDeth](https://boards.straightdope.com/u/DrDeth)
#### Post date: [April 11, 2020, 5:24pm UTC](https://boards.straightdope.com/t/trespassing-and-undercover-investigations/851108/32 "2020-04-11T17:24:36Z")
> [@UltraVires](#):
>
> …
>
> 1. You are all about fences. Trespass law in tort does not require a fence. Just notice that the entry on your property is forbidden. You think a guy that got caught shoplifting at WalMart and given a trespass notice could go back and say, “But there is no fence here!”
>
> 2. Asking a person “Are you a cop?” and have them lie to you by saying “No” is not a trespass upon your “persons, papers, houses, and effects” as stated in the Fourth Amendment. A person trespassing on your property after you have given express directives that they not enter your property is a violation of that Amendment.
It requires a notice- and a clear line. In your Walmart case, you have a “fence”- they have a door. Also he was personally given notice. Just a sign generally isnt good enough. and it certainly wouldn’t stop a police officer if it said “No cops can trespass”.
So, no, a sign saying “No cops allowed” wouldnt protect you.
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### Author:  [@DrDeth](https://boards.straightdope.com/u/DrDeth)
#### Post date: [April 11, 2020, 5:27pm UTC](https://boards.straightdope.com/t/trespassing-and-undercover-investigations/851108/33 "2020-04-11T17:27:07Z")
> [@doreen](#):
>
> …
>
> Why does Walmart (or any other place) have to issue a trespass notice to begin with? Why can’t they post a sign simply saying shoplifters aren’t permitted to enter ? And once Walmart posts such a sign, why can’t the police charge shoplifters with criminal trespass in addition to whatever charge covers the shoplifting?
Yep. That’s why such signs wont work.
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### Author:  [@UltraVires](https://boards.straightdope.com/u/UltraVires)
#### Post date: [April 11, 2020, 7:14pm UTC](https://boards.straightdope.com/t/trespassing-and-undercover-investigations/851108/34 "2020-04-11T19:14:52Z")
> [@doreen](#):
>
> Why does Walmart (or any other place) have to issue a trespass notice to begin with? Why can’t they post a sign simply saying shoplifters aren’t permitted to enter ? And once Walmart posts such a sign, why can’t the police charge shoplifters with criminal trespass in addition to whatever charge covers the shoplifting?
The problem with that is that the shoplifter will argue that they did not have the intent to shoplift when they entered, that they did it on an impulse, and there is no evidence to prove otherwise.
But, yes, when they can prove it, they do charge it. There is a Supreme Court case around here where a shoplifter left the store, took items to his car, went back in and shoplifted again and got caught. As it was pretty clear that he entered the second time with intent, he got nailed for daytime burglary.
However, my larger point still stands. You have an implied license to go into Wal Mart to browse the items that they have for sale and to buy one or more of them if you agree with the posted price. That’s it. Of course it is trespassing if you enter their store when it is closed or for the purposes of stealing their items. That is outside of your implied license to enter.
Would a reasonable person believe that Wal Mart would allow them on their property to steal? If not, the person is trespassing. Why wouldn’t it be trespassing, with or without a sign?
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### Author:  [@UltraVires](https://boards.straightdope.com/u/UltraVires)
#### Post date: [April 11, 2020, 7:28pm UTC](https://boards.straightdope.com/t/trespassing-and-undercover-investigations/851108/35 "2020-04-11T19:28:43Z")
> [@DrDeth](#):
>
> It requires a notice- and a clear line. In your Walmart case, you have a “fence”- they have a door. Also he was personally given notice. Just a sign generally isnt good enough. and it certainly wouldn’t stop a police officer if it said “No cops can trespass”.
>
> So, no, a sign saying “No cops allowed” wouldnt protect you.
You agree that as a private property owner I have the ability to exclude anyone I want to, correct? I can exclude cops if I want to–assuming that they do not have a valid search warrant or meet one of the several exceptions to the warrant requirement.
If I have that ability to exclude then there must be some meaningful way to assert that ability, and there must be an equally valid way for the poor to assert that ability. And further, I do not see how a giant sign that says “No Cops Allowed” fails to put any police officer on notice that I am excluding him.
And even with a fence, if a “snitch” gains entrance to my house through fraud, e.g. he is pretending to be my friend yet secretly working for law enforcement, then that is also a trespass even though I opened the door and invited him in. No fence in the world will keep him out.
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### Author:  [@UltraVires](https://boards.straightdope.com/u/UltraVires)
#### Post date: [April 11, 2020, 9:06pm UTC](https://boards.straightdope.com/t/trespassing-and-undercover-investigations/851108/36 "2020-04-11T21:06:21Z")
> [@doreen](#):
>
> Of course she can’t shoot him - but if you believe it’s civil trespass, why isn’t it criminal trespass? If telling him he’s only welcome under certain conditions is sufficient notice to make it civil trespass, why isn’t it enough for a criminal charge?
Sorry, I failed to respond to this one. There are several reasons. Criminal trespass is defined by law and is much more lenient that the civil tort. It generally requires a written notice to be formally served on a party with a follow up entry and creates many safeguards, or it requires an entry in unmistakeable situations (e.g. I beat down a stranger’s door and sit on their couch and claim that I didn’t know the owner didn’t want me to do that).
Further, did can she prove she told the boyfriend that? And was it stated in an absolute way? If my wife tells me I will be in the doghouse if I don’t clean the gutters, do I actually think that she will make me literally sleep in the doghouse?
Also, for as much as I bitch about prosecutors, they are not tyrants. There is no interest in the state arresting people over a relationship dispute because one party cheated. If you want him out of your house, we will serve him with this formal trespass notice and if he comes back he will be arrested, but we simply are not going to arrest him because he came over to your house after he violated a condition of entry, even if it does literally comply with the law. We aren’t filling up our jails with cheating boyfriends.
But my main point is that it is a false comparison to say that because the police will not arrest you for X that means that X is not trespassing.
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### Author:  [@DrDeth](https://boards.straightdope.com/u/DrDeth)
#### Post date: [April 11, 2020, 10:09pm UTC](https://boards.straightdope.com/t/trespassing-and-undercover-investigations/851108/37 "2020-04-11T22:09:42Z")
> [@UltraVires](#):
>
> You agree that as a private property owner I have the ability to exclude anyone I want to, correct? I can exclude cops if I want to–assuming that they do not have a valid search warrant or meet one of the several exceptions to the warrant requirement.
>
> If I have that ability to exclude then there must be some meaningful way to assert that ability, and there must be an equally valid way for the poor to assert that ability. And further, I do not see how a giant sign that says “No Cops Allowed” fails to put any police officer on notice that I am excluding him…
Sure, by a fence. Or gate.
or telling individuals in person and giving them notice.
But sorry, try asking a cop or a lawyer about your “no cops allowed” sign- they need a good laugh.
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### Author:  [@UltraVires](https://boards.straightdope.com/u/UltraVires)
#### Post date: [April 11, 2020, 10:46pm UTC](https://boards.straightdope.com/t/trespassing-and-undercover-investigations/851108/38 "2020-04-11T22:46:12Z")
> [@DrDeth](#):
>
> Sure, by a fence. Or gate.
>
> or telling individuals in person and giving them notice.
>
> But sorry, try asking a cop or a lawyer about your “no cops allowed” sign- they need a good laugh.
I am a criminal defense lawyer and I fail to see why a police officer would not be trespassing if he sees a “No Cops Allowed” sign on my driveway yet continues past it anyways (again assuming no warrant or exception to the warrant requirement). I could see there being an argument if he didn’t see it because it was obscured by a tree or by brush, but assuming he saw it, why is that not good notice to him that he is not welcome?
You keep asserting how silly it is, but I have seen no case law that says why. And Jardines seems to hold that the implied license does not extend to police investigations in general. If the implied license does not extend to a police officer with a drug sniffing dog, because it can be assumed that a homeowner would not allow that, then why couldn’t it be assumed that a homeowner would equally object to a knock and talk when the homeowner is a suspect?
What Hamlet provided above was a summary of cases that said a simple “No Trespassing” sign did not put the police or other casual visitors on notice because it is ambiguous. It is not clear if I am a Mormon and approaching the house that I would be trespassing if I came on the property, so that court held that a simple No Trespassing sign was not enough. However, the converse of the holding seems to imply that if the sign was more definite, that it would be effective notice to the police.
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### Author:  [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)
#### Post date: [April 12, 2020, 4:08am UTC](https://boards.straightdope.com/t/trespassing-and-undercover-investigations/851108/39 "2020-04-12T04:08:04Z")
> [@UltraVires](#):
>
> You keep asserting how silly it is, but I have seen no case law that says why. And Jardines seems to hold that the implied license does not extend to police investigations in general. If the implied license does not extend to a police officer with a drug sniffing dog, because it can be assumed that a homeowner would not allow that, then why couldn’t it be assumed that a homeowner would equally object to a knock and talk when the homeowner is a suspect?
That’s not the interpretation I had. My understanding is that Jardines allows police officers to approach a person’s house for the purpose of conducting a “knock and talk” because most homeowners allow the average person to approach their house for similar purposes. The Jardines decision ruled the police using a drug-sniffing dog on your property was no allowed because that’s not a purpose for which an average person would approach your house.
> [@](#):
>
> “A license may be implied from the habits of the country,” notwithstanding the “strict rule of the English common law as to entry upon a close.” McKee v. Gratz, 260 U. S. 127, 136 (1922) (Holmes, J.). We have accordingly recognized that “the knocker on the front door is treated as an invitation or license to attempt an entry, justifying ingress to the home by solicitors, hawkers and peddlers of all kinds.” Breard v. Alexandria, 341 U. S. 622, 626 (1951) . This implicit license typically permits the visitor to approach the home by the front path, knock promptly, wait briefly to be received, and then (absent invitation to linger longer) leave. Complying with the terms of that traditional invitation does not require fine-grained legal knowledge; it is generally managed without incident by the Nation’s Girl Scouts and trick-or-treaters. [2] Thus, a police officer not armed with a warrant may approach a home and knock, precisely because that is “no more than any private citizen might do.” Kentucky v. King, 563 U. S. \_\_\_, \_\_\_ (2011) (slip op., at 16).
>
> ```
> But introducing a trained police dog to explore the area around the home in hopes of discovering incriminating evidence is something else. There is no customary invitation to do that. An invitation to engage in canine forensic investigation assuredly does not inhere in the very act of hanging a knocker. [3] To find a visitor knocking on the door is routine (even if sometimes unwelcome); to spot that same visitor exploring the front path with a metal detector, or marching his bloodhound into the garden before saying hello and asking permission, would inspire most of us to—well, call the police. The scope of a license—express or implied—is limited not only to a particular area but also to a specific purpose. Consent at a traffic stop to an officer’s checking out an anonymous tip that there is a body in the trunk does not permit the officer to rummage through the trunk for narcotics. Here, the background social norms that invite a visitor to the front door do not invite him there to conduct a search.
>
> ```
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### Author:  [@Bear\_Nenno](https://boards.straightdope.com/u/Bear_Nenno)
#### Post date: [April 12, 2020, 1:08pm UTC](https://boards.straightdope.com/t/trespassing-and-undercover-investigations/851108/40 "2020-04-12T13:08:42Z")
> [@UltraVires](#):
>
> “No persons who are working for law enforcement in any capacity, or have the intention of reporting what they see or hear inside these premises, are permitted entry on these premises. Any implied license to enter for these purposes is hereby expressly revoked”?
If I’m the prosecutor, I might take a different approach. I would argue that the informant was not “working for law enforcement in any capacity”. The informant was a volunteer working for himself, and solely for his own interests. I would dig up case law in your jurisdiction to show how volunteers and private contractors are _not_ workers. I would explicitly call attention to the differences between “working for” and “working with”.
The informant did _not_ report what he saw, and did not report what he heard. He merely reported what he _did_. Reporting that he exchanged money for drugs inside the house does not involve reporting on sights and sounds. I’ll have to figure out an argument to counter the fact that you will no doubt bring up the question of identifying who he actually bought the drugs _from_, since that entails reporting what he “saw”. That’s going to depend on how many people were also there. If it was just the informant and your defendant in the home, then that will be easy for me. Especially if he is the only resident of the home, and/or he invited him over for the deal at a particular time. He can report on what he heard prior to being in the home. So if the defendant said “Come over right now for a drug deal”, and then the informant goes to the home to do the deal, I think that should be sufficient bona fides without being able to say, “I saw him specifically hand me the drugs”.
Also, was the informant wearing a wire? If so, that makes the whole thing moot because he doesn’t neat to report on what he heard. The recording will do that.
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