11.   He was forced from the post when police investigated charges he tried to persuade a witness to change testimony and lied to a court.

12.   He was forced from the post two months later, when police investigated charges he tried to persuade a witness to change testimony and lied to a court.

13.   However, the case against Cortes Vazquez is based primarily on one witness who has now changed his testimony at least three times.

14.   If he changes his testimony on the stand, he looks like a liar to the jury.

15.   I wish to change my testimony.

16.   Key witnesses changed their testimony.

17.   She is expected to change her testimony and outline the details of an Oval Office liaison with Clinton.

18.   She has changed her testimony over the past year, first saying he did not authorize any of the payments, then saying he had approved all of them.

19.   Sometimes obstruction cases are cut and dried, involving, say, destroying documents, coercing jurors or paying witnesses to change their testimony.

20.   Sometimes a lawyer surreptitiously records interviews with potential witnesses as insurance, in case witnesses change their testimony in court.