What crime is John Proctor accused of at the end of Act 3?

Proctor calls Abigail a bad name and tells the court about their affair. He then defends his wife Elizabeth by saying that she is incapable of lying. The court summons Elizabeth. When she enters the room, no one will speak and she notices that Proctor and Abigail both have their backs to her. When Danforth asks Elizabeth why she dismissed Abigail, Elizabeth lies, concealing Proctor and Abigail's affair.