A big thanks to everyone who commented on my post yesterday! I'll try to answer all your questions here.
Now, the obligatory lawyer disclaimer:
I am actually a lawyer, and as such, I my state bar association rules rightfully prohibit me from giving legal advice about the internet willy-nilly. Nothing that I am about to say should be construed as binding authority or legal advice. It is not intended that way, nor should you attempt to rely on it in any fashion. This is for two reasons: 1) if you are relying on this post, you've been charged with a crime. If that is true, you desperately need your own lawyer; and 2) it will almost certainly turn out badly for you.
In addition, the answers to these questions can vary wildly based upon jurisdictions. What is true for me probably isn't true everywhere, and may be extremely unique to my state.
One Curvy Blogger asked: how long does it really take for a DNA test to come back in a murder investigation (or any kind of criminal one)?
It varies substantially from case to case, but the minimum that I have seen is around 5 days, with the analyst basically setting aside all other work and focusing on my case. Murder cases are typically the highest priority, with priority dropping based upon seriousness. If there is no suspect, and the case is, say, a residential burglary, analysis can take months because it will keep getting reprioritized downward based on other cases needing priority. It is basically a form of triage, and analysis does not occur on a strict "your number is" basis. More like ER, less like DMV.
How often does the Miranda warning actually get disputed?
This is a good question. Miranda only applies to custodial interrogations, and it is only disputed if the defendant made inculpatory statements to the police. See what I did there, using complicated law words? "Custodial interrogation" is a legal term, and basically means either in actual or constructive custody of the police (like, in handcuffs and stuff). Whether a given set of facts constitutes "custodial interrogation" has been the subject of literally thousands of legal opinions. Inculpatory statements are statements that make the defendant look guilty.
I only offer statements of the defendant if they make him look guilty - if he wants the jury to hear his self-serving bullshit, he can testify. And then I get to cross-examine him.
So, if no statements were made, no need for Miranda and there won't be any kind of a hearing. And if it is obvious that Miranda was given, there won't be any need for a hearing. That gray zone of cases where Miranda wasn't given, the defendant made admissions or a confession, and there are some facts to support an argument that he was in custody or that the statements was involuntary in some other way. Those are litigated.
And then there are the cases where it is just as painfully plain as fucking day that the officer violated Miranda. In those cases, I concede the motion and don't use the statements.
How are decisions really made about what evidence can be presented?
This is super complicated because the rules of evidence cover everything from when the rules of evidence apply (not pretrial hearings, not sentencing hearings) to how lawyers authenticate evidence (chain of custody of evidence to be tested, physical objects, photographs and papers) to allowable character evidence (when can the lawyers present evidence that someone is a lying liar who lies) to hearsay (stuff people said outside of court).
The rules themselves are probably 100 pages long. The authoritative text in my jurisdiction that goes through the rules, the commentary to the rules, and an analysis of the rules with case citations is 1005 pages long. The body of case law is so extensive that no lawyer can possibly read every case, even in their own jurisdiction.
Generally, we argue out some of the evidentiary issues before trial begins through motions to suppress (motions that claim that the police seized the evidence illegally) or through motions in limine (motions to exclude or offer evidence that we recognize will be contentious), and we argue out other evidentiary issues during the trial itself, with objections and offers of proof outside the presence of the jury.
I am not familiar with the Collins case. Maybe you can expand on the question and point me in the right direction.
How often does it happen that you (or prosecutors in general, whatever) have cases where they don't believe in the defendant's guilt? If this happens, what does the prosecutor tend to do?
This is a great question! Thanks for asking it. It is also really easy to answer because the answer is never. There is something called "prosecutorial discretion" that basically means that I don't file a case unless two things are true: I believe I can prove the crime beyond a reasonable doubt, and I believe that the defendant is guilty. If both of those factors aren't present, the case never gets beyond the review stage - prosecution is declined.
Prosecutor is a very powerful position. I cannot be forced to file a case I do not believe is meritorious, and I cannot be forced to dismiss a case that I believe is legitimate. As was said to Batman Spiderman, with great power comes great responsibility. We have a whole code of ethics that applies to us that tells us what our ethical boundaries are and violating them is going to get us into trouble. The goal is always to hold the guilty responsible and to ensure that justice is accomplished. No one ever wants to learn that their prosecution caused a person to go to prison for something he/she didn't do. That would be devastating.
There can also be the situation that, after it has been presented to the grand jury and indicted, new evidence is uncovered that demonstrates that the case lacks merit - that the defendant is actually innocent. In that situation, the only possible ethical response to the finding is that the prosecutor must dismiss the case.
Private Investigators - is information they gather able to be used in prosecutions?
I get my cases from the police - a private citizen can't just wander in and hand me a bunch of stuff and tell me to go charge his neighbor with trespassing. I have never had a case where I used evidence obtained by private investigators.
However, a PI is just a private citizen and would be a witness like any other witness. Their status as a PI doesn't give them more or less credibility than anyone else.
In my jurisdiction, defense attorneys will use defense investigators (we don't actually call them private investigators) to interview witnesses, take pictures, etc. They can be called as witnesses, and their testimony is treated just like everyone else's. The only difference is that they are not state actors, so if they violate someone's constitutional rights, the evidence they gather is not subject to a motion to suppress.
Thanks for playing!