I strongly suggest you obtain counsel if you have been subpoenaed to provide information about another person's criminal conduct, particularly if the information you have could tend to incriminate you in any way.
The 5th Amendment to the U.S. Constitution provides that no one "shall be compelled in any criminal case to be a witness against himself." This applies both to grand jury proceedings and trials.
By discussing the facts of the case with your attorney, he or she can advise you as to whether you have any criminal exposure in the case. If you do, your attorney can inform the prosecutor of your intent to refuse to answer questions based on your 5th Amendment privilege. The prosecutor may decide to provide you with formal or informal immunity -- a legal promise not to charge you with any crime -- in exchange for your truthful testimony. Formal immunity is done by statute and court order, according to the law of the jurisdiction. If the prosecutor wants to provide you with informal immunity, usually done by letter agreement, your lawyer should review it to make sure are fully protected. For example, there may be issues with respect to whether the prosecution can charge you with a crime after you have testified, if it relies on information obtained from a source other than your testimony.
If you do not have any criminal exposure, but merely want to avoid implicating a friend in a crime, your options are far more limited. But here again, an experienced criminal lawyer may be able to negotiate an acceptable resolution with the prosecutor.
The biggest mistake you can make is ignoring the subpoena or failing to show up at the appointed time. The court is likely to issue a warrant for your arrest.
-- Jeralyn Merritt
