What kind of word-of-mouth evidence requires a subpoena, and which doesn't?

Sometimes a crime is prosecuted with simple casual “Oh, this bystander says he or she saw something happen” testimony jotted by a cop on a notebook and sometimes it takes a really formal subpoena with a really formal written document for a testimony to be accepted.

What’s the dividing line? Which kind of testimony is acceptable, regardless of how casually it was obtained, and what kind is not acceptable unless it is really formal?

I’m pretty sure you can’t actually be tried with the notes of the investigating officer serving as evidence of what someone else SAID they witnessed.

I am not a lawyer, but I think you are mixing things up more than a little. I don’t think any court case would admit testimony from a cop about what someone else said, based on notes he made or not, rather than from calling the original source up to testify*. A cop’s notes are a starting place for an investigation of a crime, not admissible evidence (under most circumstances, and remember, IANA lawyer).

*I don’t know what happens if the original source’s testimony conflicts with what they told the cop during the investigation. Nothing much in court, is my guess, because what they told the cop before is not admissible.

It’s complicated. The officer’s notes themselves are unlikely to be admitted. But let’s say there was a car accident. Officer testified that he heard the defendant say, “I am so drunk!” The officer also heard the defendant’s passenger hysterically yell at the defendant, “You crashed my car and hurt those people!”

Both of those statements could be admitted at a criminal trial of the defendant for crimes associated with the crash.

The defendant’s statement is admissible as a party opponent statement. The passenger statement could be admitted under the excited utterance exception to the hearsay rule.

Having the passenger testify about what happened is better, but imagine that the passenger is now saying someone else was driving the car, or they can’t be found to serve with a subpoena. Now that excited utterance is important.

If there isn’t an exception that applies to the hearsay statements, then the party wanting that testimony needs to call the witness.

A subpoena is a way to force someone to come to court and testify, or to produce documents. It doesn’t go to the admissibility of the evidence, and it may not be necessary if you have a cooperating witness.

What I meant was something more like this:

Say John Doe is accused of some crime. And the feds decide to check around on Doe’s social media to see if anyone knows anything. They chat up his best friend, “Hey, do you know of anything?” And his best friend says “Ah yes, John told me about…(this and that).”

Presumably, that evidence would be considered too “casual” to be admitted as evidence in discovery or trial. Do the feds need to “solidify” it further by making a deposition out of it?

Just observing that in law school I took a semester long course in Evidence, ad a good part of that concerned hearsay and exceptions. Good luck in getting a snapshot explanation here.

Just today, there was an article in the Chicago paper about Illinois’ unusual hearsay exception WRT the Drew Peterson murder conviction. As eschrodinger says, it is complicated.

But it would help if you actually looked up a bit about hearsay, and used terms relevant to that topic, rather than “casual” and “solidify.”

Taking a deposition doesn’t have anything to do with it. And as Dinsdale says, terms like “casual” and “solidify” don’t have any recognizable connection to hearsay rules.

You could subpoena the friend, and they could recount the defendant’s statements to the jury. (Party opponent statements.)

If you called the officer, it’s complicated because you have double hearsay. The officer saying what the friend said the defendant said.

You need a basis to admit both layers of the hearsay to get any of it in. Party opponent works on the defendant’s statements layer, but you’d need another basis to get the friend statements layer. This is one of the bases for the hearsay rule itself – if you can call the witness, you should call the witness to testify directly. To get statements in a different way, you need a good reason, and reason to believe the statements are reliable.

Ah, I see.

With a victim, it would be far simpler, right?

Feds: “Hey, did John Doe ever assault you before?”

Victim: “Yep, in 2014.”

Feds: “OK good, let’s get a formal deposition about it.”

Again, it’s not about depositions. In fact, a written deposition transcript would often be hearsay itself.

Maybe I don’t understand what you’re asking. Casual and formal are not dividing lines for admission of testimony in a criminal case.

And you would very nearly always want the victim to testify in court in front of the jury if they are capable of doing so – not put in a deposition, even if it were admissible.

Are you still talking about admissibility of evidence, or are you thinking more about sufficiency?

Let’s say Joe is cooking meth in his garage and selling it to friends and acquaintances. He’s been busted for possession before, but he’s never been caught cooking or dealing. One night he brags about the fat stacks he’s making to his new ladyfriend, hoping to impress her. Instead, she tells the cops.

Now, the police could probably get a search warrant based on that info, assuming it was specific enough. They might even get an arrest warrant, and if they didn’t get a confession out of him or find any other evidence but the DA still wanted to take it to trial, they could have the ladyfriend testify as to what he told her. (Though “so-and-so told me” is generally hearsay, there are exceptions that make both party admissions and also statements against interest admissible.) They wouldn’t necessarily need to subpoena her or do anything else to make her testimony more “solid.” And if the jury found her really credible, theoretically, they could convict.

But realistically, that’s a bad strategy. Criminal charges require proof beyond a reasonable doubt, and Joe’s defense attorney would likely shred the ladyfriend’s credibility on cross-examination, and offer the jury plausible alternative scenarios (he was making up stories to try to impress her, she was mad because he dumped her so she tried to get him thrown in jail, etc.) The smart way to go would be to use her statements to get a warrant, then go find Joe’s actual lab, photograph and catalog the physical evidence, have the cop testify to what was found, where, and the chain of custody, have experts testify that this was indeed meth inside the coffee pot with Joe’s fingerprints inside Joe’s garage, etc. Or maybe use that tip to tail Joe until you catch him in a sale, and have the cop testify about that. Maybe offer his buyer a plea in exchange for testifying against him also. You’re probably going to want to subpoena that guy, and prep him well for testimony. Not because his testimony wouldn’t otherwise be admissible, but because you don’t want him screwing everything up.