The key is the difference between factual guilt (what the defendant actually did) and legal guilt (what a prosecutor can prove). A good criminal defense lawyer asks not, “Did my client do it?” but rather, “Can the government prove that my client did it?” No matter what the defendant has done, he is not legally guilty until a prosecutor offers enough evidence to persuade a judge or
jury to convict.
However, the defense lawyer may not lie to the judge or jury by specifically stating that the defendant did not do something the lawyer knows the defendant did do. (On the other hand, the lawyer cannot
admit guilt against the client's wishes.) Rather, the lawyer’s trial tactics and arguments must focus on the government’s failure to prove all the
elements of the crime.
Example: Sam is charged with shoplifting. Sam admits to his lawyer that he took a watch, as charged. Sam’s lawyer realizes that the store’s hidden camera videotape is fuzzy and practically useless as prosecution evidence. In addition, Sam’s lawyer learns that the store’s security guard was at the end of a long overtime shift and had been drinking alcohol. Sam’s lawyer can use these facts in an argument for Sam’s acquittal. Before trial, Sam’s lawyer can argue to the D.A. that the D.A.’s case is too weak to prosecute. At trial, Sam’s lawyer can argue to a judge or jury to acquit Sam. No matter what Sam has done, Sam is not legally guilty unless the prosecutor can prove it beyond a reasonable doubt.
But Sam’s lawyer cannot ethically state in his argument that Sam “didn’t do it,” only that the D.A. didn’t prove that Sam did do it. While the line between ethical and unethical behavior may seem like—indeed, is—a fine one, it is a line that criminal defense lawyers walk every day on the job.
