A homeless man has pleaded not guilty to attacking and threatening to kill "NCIS" actress Pauley Perrette.
Forty-five-year-old David Merck entered pleas Monday to false imprisonment by violence and making a criminal threat.
He could face up to four years in prison if convicted.
Perrette said a man she described as psychotic and homeless repeatedly punched her in the face and threatened to kill her outside her Hollywood home last Thursday.
She said a friend tracked down and followed the man until police arrived.