# Do police need a search warrant to investigate a crime scene? **URL:** \ **Category:** Factual Questions\ **Created:** [December 15, 2025, 1:49pm UTC](https://boards.straightdope.com/t/do-police-need-a-search-warrant-to-investigate-a-crime-scene/1025722 "2025-12-15T13:49:04Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [December 15, 2025, 8:44pm UTC](https://boards.straightdope.com/t/do-police-need-a-search-warrant-to-investigate-a-crime-scene/1025722/21 "2025-12-15T20:44:51Z")
> [@glee](#): > > Suppose a pedestrian is murdered on a busy street. > Can’t the police start searching? (If it’s a public place, presumably different rules apply…) Yes, of course. Public place. And the police can examine the body etc in a private home. But expanding that search to the rest of the house might require a warrant. IANAL, and it depends. For example- dead body, and then tracks leading to a broken window where the perp got it. They do not need a warrant to check out that. > [@Loach](#): > > Take something like the current Reiner case as a hypothetical. Let’s say the living room is the crime scene. The son is living in the house. Is his living area considered separate from the rest of the residence? Does probable cause cover that or not? Can you do a cursory search or can you go into drawers and closets? Does it cover electronic devices? Without exigent circumstances it is easy to pick holes in any search. The house should be cleared for safety. Make sure no one else is there. Anything in plain view should be noted and seized for evidence. Then the residence should be secured and a warrant obtained. The victims aren’t getting any deader. Great post. ---
**Author:** ![doreen](https://avatars.discourse-cdn.com/v4/letter/d/858c86/32.png) [@doreen](https://boards.straightdope.com/u/doreen)\ **Post date:** [December 15, 2025, 9:10pm UTC](https://boards.straightdope.com/t/do-police-need-a-search-warrant-to-investigate-a-crime-scene/1025722/22 "2025-12-15T21:10:42Z")
> [@Loach](#): > > And in the Reiner case apparently the accused lived in the house. His 4th amendment rights don’t go away because a crime was committed. That I think is the biggest issue in this case , that the accused is their son, who may have been living there. Let’s say the police got their and found a complete stranger standing over the bodies. The house was clearly broken into. If the police search that house without a warrant and found the knife he used in a kitchen drawer, he can’t object to the search. He has no Fourth Amendment rights in someone else’s house where he doesn’t live. But their son ? Search without a warrant and there’s a good chance that whatever you find won’t be admissible. Even if he didn’t actually live there , there’s a good chance that he stands to inherit the house along with his siblings. And given how easy it will be to get a search warrant, might as well not take any chances and get the warrant even if the accused is a stranger. ---
**Author:** ![Loach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/loach/32/350_2.png) [@Loach](https://boards.straightdope.com/u/Loach)\ **Post date:** [December 16, 2025, 2:22am UTC](https://boards.straightdope.com/t/do-police-need-a-search-warrant-to-investigate-a-crime-scene/1025722/23 "2025-12-16T02:22:02Z")
> [@griffin1977](#): > > > [@Loach](#): > > > > This explains some of the case law. > > > > [https://www.fletc.gov/sites/default/files/imported\_files/training/programs/legal-division/downloads-articles-and-faqs/research-by-subject/4th-amendment/murdersceneexception.pdf](https://www.fletc.gov/sites/default/files/imported_files/training/programs/legal-division/downloads-articles-and-faqs/research-by-subject/4th-amendment/murdersceneexception.pdf) > > Thanks that makes sense. Though i’d still bet if this was a random dude who’d stabbed his dad in a crappy apartment in South Central, the LAPD would not be bending over backwards to follow the exact letter of the law (and to publicly do so) I wouldn’t be so sure. It’s not like you can pretend that you got a search warrant later. LA and other big cities have detectives dedicated to homicides. Putting together a search warrant when you aren’t used to doing it can be a pain in the ass. When you are doing it daily and have easy access to lawyers and a judge it’s just a routine part of the job. Dealing with cases involving random dudes in South Central is just another Tuesday. ---
**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\ **Post date:** [December 16, 2025, 3:08am UTC](https://boards.straightdope.com/t/do-police-need-a-search-warrant-to-investigate-a-crime-scene/1025722/24 "2025-12-16T03:08:52Z")
First I am not trying to argue what the law does or doesn’t say. I am just surprised and tainted by watching 60 years of police procedural movies and TV shows. Never once in a fictional crime story have I see the police get a search warrant before searching any crime scene for evidence. Obviously that would be an inconvenient delay in the storytelling. I am trying to understand what happens in the real world. > [@Loach](#): > > Take something like the current Reiner case as a hypothetical.[…]the residence should be secured and a warrant obtained. So you can’t search the place because it is the residence of the son, maybe even owned by him, but you can seal it and tell him he can’t go in his own house, which you are not allowed to search? What allows you to seal it and deny him access, yet at the same time is insufficient to allow a search without a warrant? ---
**Author:** ![NoSleepTillDeath](https://avatars.discourse-cdn.com/v4/letter/n/a87d85/32.png) [@NoSleepTillDeath](https://boards.straightdope.com/u/NoSleepTillDeath)\ **Post date:** [December 16, 2025, 3:39am UTC](https://boards.straightdope.com/t/do-police-need-a-search-warrant-to-investigate-a-crime-scene/1025722/25 "2025-12-16T03:39:49Z")
Yes he still has his Constitutional protection from unreasonable search and seizure, but you don’t have the right to go through an active crime scene and potentially tamper with/ destroy evidence because it’s your residence. Even if he wasn’t at all connected to the crime, just wandering through a crime scene will destroy/contaminate/alter evidence. ---
**Author:** ![Curiousgrace](https://avatars.discourse-cdn.com/v4/letter/c/f08c70/32.png) [@Curiousgrace](https://boards.straightdope.com/u/Curiousgrace)\ **Post date:** [December 16, 2025, 4:17am UTC](https://boards.straightdope.com/t/do-police-need-a-search-warrant-to-investigate-a-crime-scene/1025722/26 "2025-12-16T04:17:09Z")
Where I live and work, two things often come up: - something was in plain view - reasonable, articulable suspicion It is really hard for a house to be part of those, but I’ve been in hearings where it’s at issue. Doesn’t seem like the case here though c: ---
**Author:** ![griffin1977](https://avatars.discourse-cdn.com/v4/letter/g/977dab/32.png) [@griffin1977](https://boards.straightdope.com/u/griffin1977)\ **Post date:** [December 16, 2025, 4:24am UTC](https://boards.straightdope.com/t/do-police-need-a-search-warrant-to-investigate-a-crime-scene/1025722/27 "2025-12-16T04:24:56Z")
> [@NoSleepTillDeath](#): > > the right to go through an active crime scene and potentially tamper with/ destroy evidence because it’s your residence But the 4th amendment covers unreasonable search **and seizure**. If your home being a crime scene isn’t an exception to the search bit, why is it an exception to the seizure bit? The police saying “we’ve sealed your home as a crime scene, and so you can’t come in” sounds like a seizure to me. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [December 16, 2025, 5:13am UTC](https://boards.straightdope.com/t/do-police-need-a-search-warrant-to-investigate-a-crime-scene/1025722/28 "2025-12-16T05:13:35Z")
> [@CookingWithGas](#): > > Never once in a fictional crime story have I see the police get a search warrant before searching any crime scene for evidence. You can certainly search the area, and a cursory search elsewhere to make sure nobodies hiding, but, if the killing is downstairs, and you go upstairs, open drawers and find a bag of pot under some socks- it is NOT admissible. > [@Curiousgrace](#): > > Where I live and work, two things often come up: > > - something was in plain view > - reasonable, articulable suspicion Yep, something in another room in a drawer or a closet would be out. > [@CookingWithGas](#): > > So you can’t search the place because it is the residence of the son, maybe even owned by him, but you can seal it and tell him he can’t go in his own house, which you are not allowed to search? What allows you to seal it and deny him access, yet at the same time is insufficient to allow a search without a warrant? It is a crime scene, where two murders occurred. You can seal it off. > [@griffin1977](#): > > The police saying “we’ve sealed your home as a crime scene, and so you can’t come in” sounds like a seizure to me. It is not. It still belongs to you and the police can only hold it for a reasonable period. ---
**Author:** ![ASL\_v2.0](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asl_v2.0/32/3525_2.png) [@ASL\_v2.0](https://boards.straightdope.com/u/ASL_v2.0)\ **Post date:** [December 16, 2025, 5:25am UTC](https://boards.straightdope.com/t/do-police-need-a-search-warrant-to-investigate-a-crime-scene/1025722/29 "2025-12-16T05:25:52Z")
> [@CookingWithGas](#): > > First I am not trying to argue what the law does or doesn’t say. I am just surprised and tainted by watching 60 years of police procedural movies and TV shows. Never once in a fictional crime story have I see the police get a search warrant before searching any crime scene for evidence. How many police procedural shows have the first police showing up at the scene also doing the search? What I am used to, the detectives arrive and the crime scene has already been secured by uniformed police, and they begin by asking the uniformed police what’s going on. Not only would I not rely on a police procedural to be technically correct when it comes to the Constitution, but it’s also entirely plausible the warrant requirement gets taken care of off-screen, between when first responders arrive to a report of a crime and when detectives show up to do their detecting. Consider also that the 4th amendment really only applies where a defendant has a reasonable expectation of privacy. If a murder truly is committed by a random stranger, such as during a burglary gone wrong, then they simply will not have an expectation of privacy, so even a warrantless search of the victim’s home would create no problems from a strictly 4th amendment perspective. That said, the police cannot necessarily rule out that the perpetrator _does_ have a reasonable exception of privacy until _after_ the search is complete and evidence gathered (for example, maybe the investigation determines that the crime was only staged as a burglary, and the perpetrator was actually someone who lives in the home)p and had an expectation of privacy). So it would make sense to, in general, get a warrant prior to conducting any search of a private residence. And that appears to have been especially relevant here because, as noted, it’s quite possible that the alleged perpetrator (the son) had and has a reasonable expectation of privacy at the crime scene if he was in fact living there as well. ---
**Author:** ![Loach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/loach/32/350_2.png) [@Loach](https://boards.straightdope.com/u/Loach)\ **Post date:** [December 16, 2025, 6:31am UTC](https://boards.straightdope.com/t/do-police-need-a-search-warrant-to-investigate-a-crime-scene/1025722/30 "2025-12-16T06:31:26Z")
> [@ASL\_v2.0](#): > > That said, the police cannot necessarily rule out that the perpetrator _does_ have a reasonable exception of privacy until _after_ the search is complete and evidence gathered (for example, maybe the investigation determines that the crime was only staged as a burglary, and the perpetrator was actually someone who lives in the home)p and had an expectation of privacy). So it would make sense to, in general, get a warrant prior to conducting any search of a private residence. And that appears to have been especially relevant here because, as noted, it’s quite possible that the alleged perpetrator (the son) had and has a reasonable expectation of privacy at the crime scene if he was in fact living there as well. Everyone has 4th amendment rights. Even the victim. Generally at a crime scene the victim will consent to the forensic search of the scene. But if they don’t consent that doesn’t mean a search can happen just because they are not currently the suspect. ---
**Author:** ![Loach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/loach/32/350_2.png) [@Loach](https://boards.straightdope.com/u/Loach)\ **Post date:** [December 16, 2025, 6:39am UTC](https://boards.straightdope.com/t/do-police-need-a-search-warrant-to-investigate-a-crime-scene/1025722/31 "2025-12-16T06:39:16Z")
> [@griffin1977](#): > > The police saying “we’ve sealed your home as a crime scene, and so you can’t come in” sounds like a seizure to me. Yes but it’s allowable seizure for a reasonable time to secure a warrant. Not indefinitely. For it to be allowed probable cause must exist and probable cause is the threshold for a search warrant. There also has to be exigency such as the probable destruction of evidence. There is caselaw on this. I’m thinking it’s part of Segura v US but it’s too late for me to slog through the entire decision. ---
**Author:** ![md-2000](https://avatars.discourse-cdn.com/v4/letter/m/9d8465/32.png) [@md-2000](https://boards.straightdope.com/u/md-2000)\ **Post date:** [December 16, 2025, 1:08pm UTC](https://boards.straightdope.com/t/do-police-need-a-search-warrant-to-investigate-a-crime-scene/1025722/32 "2025-12-16T13:08:41Z")
I’m sure I’ve seen police shows where the issue arose - “that’s my room, not his. You can’t search there.” It would require a separate set of consent or warrant. ---
**Author:** ![Telemark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/telemark/32/372_2.png) [@Telemark](https://boards.straightdope.com/u/Telemark)\ **Post date:** [December 16, 2025, 1:49pm UTC](https://boards.straightdope.com/t/do-police-need-a-search-warrant-to-investigate-a-crime-scene/1025722/33 "2025-12-16T13:49:00Z")
> [@md-2000](#): > > I’m sure I’ve seen police shows where the issue arose Police procedurals tend to avoid details unless they contribute directly to the plot. If obtaining a search warrant is a critical detail in this case, they’ll go over the process. If it’s not, they’ll just handwave it. It’s Chekhov’s search warrant. ---
**Author:** ![scudsucker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/scudsucker/32/14101_2.png) [@scudsucker](https://boards.straightdope.com/u/scudsucker)\ **Post date:** [December 16, 2025, 2:11pm UTC](https://boards.straightdope.com/t/do-police-need-a-search-warrant-to-investigate-a-crime-scene/1025722/34 "2025-12-16T14:11:05Z")
> [@Loach](#): > > It’s not about privacy. It’s about mobility Not being an American, this is not an issue for me - but does that not in theory allow any trailer park home to be invaded by police? They are (technically & theoretically) mobile even if they have been on the same lot for 20+ years. ---
**Author:** ![ASL\_v2.0](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asl_v2.0/32/3525_2.png) [@ASL\_v2.0](https://boards.straightdope.com/u/ASL_v2.0)\ **Post date:** [December 16, 2025, 2:16pm UTC](https://boards.straightdope.com/t/do-police-need-a-search-warrant-to-investigate-a-crime-scene/1025722/35 "2025-12-16T14:16:12Z")
> [@Loach](#): > > Everyone has 4th amendment rights. Even the victim. Generally at a crime scene the victim will consent to the forensic search of the scene. But if they don’t consent that doesn’t mean a search can happen just because they are not currently the suspect. And yet, as a _Constitutional_ matter, only the accused has a remedy for a violation of the 4th amendment. A victim, their family, or some third party property owner cannot sue to have the fruits of an unconstitutional search thrown out at trial. That is simply the point I am trying to make. Perhaps too narrowly by not considering things like trespassing and other statutory limits or concerns, but true nevertheless. ---
**Author:** ![doreen](https://avatars.discourse-cdn.com/v4/letter/d/858c86/32.png) [@doreen](https://boards.straightdope.com/u/doreen)\ **Post date:** [December 16, 2025, 3:40pm UTC](https://boards.straightdope.com/t/do-police-need-a-search-warrant-to-investigate-a-crime-scene/1025722/36 "2025-12-16T15:40:13Z")
> [@scudsucker](#): > > Not being an American, this is not an issue for me - but does that not in theory allow any trailer park home to be invaded by police? > > They are (technically & theoretically) mobile even if they have been on the same lot for 20+ years. They are theoretically mobile, but I’ve never seen one that actually is , and certainly not in the way a car is, by simply turning an ignition key. They don’t have license plates and registrations like a vehicle. They aren’t self-propelled and they need to be towed. A [motor home](https://en.wikipedia.org/wiki/Motorhome) on the other hand does require only a turn of the ignition key and there’s a Supreme Court [case](https://supreme.justia.com/cases/federal/us/471/386/) that said a search of a motor home parked in a lot in downtown San Diego ( not a trailer park) fell under the vehicle exception. That decision distinguishs this motor home from the typical single or double-wides in a trailer park > We need not pass on the application of the vehicle exception to a motor home that is situated in a way or place that objectively indicates that it is being used as a residence. Among the factors that might be relevant in determining whether a warrant would be required in such a circumstance is its location, whether the vehicle is readily mobile or instead, for instance, elevated on blocks, whether the vehicle is licensed, whether it is connected to utilities, and whether it has convenient access to a public road. ---
**Author:** ![Loach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/loach/32/350_2.png) [@Loach](https://boards.straightdope.com/u/Loach)\ **Post date:** [December 16, 2025, 3:57pm UTC](https://boards.straightdope.com/t/do-police-need-a-search-warrant-to-investigate-a-crime-scene/1025722/37 "2025-12-16T15:57:15Z")
> [@scudsucker](#): > > > [@Loach](#): > > > > It’s not about privacy. It’s about mobility > > Not being an American, this is not an issue for me - but does that not in theory allow any trailer park home to be invaded by police? > > They are (technically & theoretically) mobile even if they have been on the same lot for 20+ years. It’s never come up for me but I know there is caselaw. I just don’t know it off the top of my head ---
**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\ **Post date:** [December 16, 2025, 4:46pm UTC](https://boards.straightdope.com/t/do-police-need-a-search-warrant-to-investigate-a-crime-scene/1025722/38 "2025-12-16T16:46:51Z")
> [@ASL\_v2.0](#): > > it’s also entirely plausible the warrant requirement gets taken care of off-screen But it’s never mentioned, not even in passing. We can assume that to allow suspension of disbelief, but it’s like when they show a software developer loading fresh code right into production with no debugging (e.g., Blind Spot), or how characters always end a phone conversation by just hanging up instead of saying good-bye. It glosses over the warts but it does give the naive viewer a distorted idea of what goes on. ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [December 16, 2025, 5:20pm UTC](https://boards.straightdope.com/t/do-police-need-a-search-warrant-to-investigate-a-crime-scene/1025722/39 "2025-12-16T17:20:18Z")
Police procedurals sometimes get into “inevitable discovery”: that is, the police screwed up on getting the warrant first but as a mere procedural error when the evidence in question would have come to light anyway. ---
**Author:** ![Loach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/loach/32/350_2.png) [@Loach](https://boards.straightdope.com/u/Loach)\ **Post date:** [December 16, 2025, 5:51pm UTC](https://boards.straightdope.com/t/do-police-need-a-search-warrant-to-investigate-a-crime-scene/1025722/40 "2025-12-16T17:51:54Z")
> [@Loach](#): > > > [@scudsucker](#): > > > > > [@Loach](#): > > > > > > It’s not about privacy. It’s about mobility > > > > Not being an American, this is not an issue for me - but does that not in theory allow any trailer park home to be invaded by police? > > > > They are (technically & theoretically) mobile even if they have been on the same lot for 20+ years. > > It’s never come up for me but I know there is caselaw. I just don’t know it off the top of my head Looks like the case is Carney v California. The main factor isn’t if it is your residence, it’s mobility. So if you are living fulltime in an RV that can be readily moved, the automobile exemption is in place. If you are in a double wide trailer permanently placed in a trailer park it does not. > [@Lumpy](#): > > Police procedurals sometimes get into “inevitable discovery”: that is, the police screwed up on getting the warrant first but as a mere procedural error when the evidence in question would have come to light anyway. I only had to deal with inevitable discovery once. Luckily it was successful. It’s a hard hill to climb. It wasn’t a warrant issue it was an issue with an interview where part of it was thrown out. It was determined that we would have found the body anyway. [Previous page](https://boards.straightdope.com/t/do-police-need-a-search-warrant-to-investigate-a-crime-scene/1025722.md?page=1) [Next page](https://boards.straightdope.com/t/do-police-need-a-search-warrant-to-investigate-a-crime-scene/1025722.md?page=3)