Can the Defense Interview a Prosecution Witness?

The defense can ask, but the witness doesn't have to agree to an interview.

By , UCLA Law School Professor
Updated by Rebecca Pirius, Attorney · Mitchell Hamline School of Law

In addition to using court discovery procedures to obtain evidence from the prosecution, defense attorneys have a duty to investigate their clients' cases. Effective lawyers will gather evidence of their own in preparation for trial—and even to see whether the client has a reasonable chance of winning at trial.

Defense investigation methods can be as informal as talking to potential witnesses on the telephone or as formal as serving a cellphone company with a subpoena demanding call logs. One method that's often effective is in-person interviews of those who know about either the events underlying the charges or the people involved in the case. This includes interviewing even those who might testify for the prosecution.

What Is a Prosecution Witness?

While witnesses don't belong to either side, a "prosecution witness" refers to someone who may be called to testify by the prosecutor (the government) in a criminal case. These witnesses can be expert or lay (non-expert) witnesses, such as the victim, witnesses to the crime, the arresting police officer, a toxicologist, or a doctor who attended to the victim or conducted an autopsy. Typically, both sides must provide a list of all the witnesses they plan to call to testify in the case.

Does the Defendant Have a Right to Interview Prosecution Witnesses?

While it's perfectly legal for defense attorneys and their investigators to interview prosecution witnesses, defendants don't generally have a right to interview a witness. It's usually up to witnesses and victims to decide whether to talk to the defense before trial. They might not be willing to talk, but a defense attorney or investigator who doesn't ask often doesn't know.

And even though prosecutors might not want their witnesses—including police officers and victims—to talk to the defense, they typically can't stop them (though they may "inform" them that they don't need to consent to an interview).

What Are the Advantages of Interviewing Prosecution Witnesses?

The defense can gain significant benefits from trying to interview prosecution witnesses rather than relying on their statements. These include the ability to:

  • gauge witnesses' demeanor and credibility
  • ferret out details of witnesses' stories and strategize as to how to handle their testimony at trial
  • impeach witnesses who say something on the stand that's inconsistent with what they told the defense
  • establish a foundation for arguing witnesses who refuse to speak to the defense are biased against the defendant, and
  • find leads for new evidence and people to interview.

A defendant might wonder whether it's worth it to interview a witness who has already given a statement that the prosecution has disclosed. But prosecutors and police officers sometimes omit or misstate information (either intentionally or not). Further, when law enforcement and prosecutors speak to witnesses, they aren't likely to ask questions that could elicit information the defense would like to know. And there might not be a record of all conversations witnesses have had with the other side.

What Options Does the Defense Have to Get a Reluctant Witness to Talk?

The defense has limited options for trying to interview uncooperative prosecution witnesses before trial. The defense lawyer might hire a private investigator who specializes in finding and interviewing reluctant witnesses. (A defense attorney might be capable of persuading a hesitant witness to talk, but will typically prefer to have someone else try, or at least be present during the conversation—that way the lawyer doesn't have to testify if the witness says something new or inconsistent at trial.)

Private investigators can drive up the cost of a case, but they're often worth the money. For those defendants who can't afford investigators or even attorneys, the court might in some instances (usually serious cases) appoint a free-of-charge investigator. Public defenders' offices typically have investigators who work on various clients' cases, but their workload often limits what they can do.

In some jurisdictions, the defense can serve witnesses with subpoenas that compel them to answer questions at a deposition (an out-of-court session at which the witness may be questioned under oath). Depositions are common in civil cases, but far less frequent in criminal cases: Most jurisdictions don't allow criminal depositions.

Defendants Should Not Interview Witnesses

Defendants themselves should almost never interview witnesses, particularly victims. Whatever the defendant says to the witness or victim can usually be mentioned at trial. And if the witness tells a different story at trial, the defendant might be forced to testify to controvert it. (The testimony might open the defendant up to difficult questioning and the jury might be inclined to believe the non-defendant witness in a battle of words.)

Furthermore, regardless of the defendant's intent, an alleged victim may interpret any personal contact as a threat, which, if reported to the authorities, can involve big trouble (including, but not limited to, revocation of bail and new criminal charges).

Lastly, a criminal defense lawyer or investigator is likely to ask the most relevant questions and get the most helpful information. As with all criminal law issues, it's best to rely on a good defense attorney's judgment.

Get a Lawyer

If you're facing criminal charges, consult an experienced criminal defense lawyer who can protect your rights and effectively investigate your case. An attorney will also be able to tell you what you should—and shouldn't—do to help. For example, your lawyer may ask you to provide all the information you can possibly think of regarding witnesses, locations, events, and even people who have nice things to say about you (who can be relevant not only at trial but also at potential sentencing).

Talk to a Defense attorney
We've helped 95 clients find attorneys today.
There was a problem with the submission. Please refresh the page and try again
Full Name is required
Email is required
Please enter a valid Email
Phone Number is required
Please enter a valid Phone Number
Zip Code is required
Please add a valid Zip Code
Please enter a valid Case Description
Description is required

How It Works

  1. Briefly tell us about your case
  2. Provide your contact information
  3. Choose attorneys to contact you