There can be multiple co-defendants in a criminal case. ... A prosecutor may offer a co-defendant a plea agreement to testify against or "flip" against the other co-defendants in a case. If the case proceeds to trial, lawyers for a co-defendant may have different strategies for defending the case.

Can two defendants testify against each other?

There's cases called Aranda-Bruton Rule. These cases stand for the proposition that yes, at a preliminary hearing a co-defendant's statement can come in against another co-defendant and against them as an admission even if the defense attorney doesn't have an opportunity to cross-examine that co-defendant.

Are co-defendants tried together?

A joint trial of codefendants (also known as "joinder") occurs when a judge merges the cases of two or more defendants. Joint trials happen when the issues in the defendants' cases overlap enough to make a single trial both fair and more efficient.