Heard was found dead in a hotel in Palo Alto, California, by a maid service on Friday, July 21, reports tmz.com.
According to his representative, Heard was recovering at the hotel after undergoing back surgery. Police were called to the hotel for a report of a medical emergency, but he was pronounced dead on the scene.
The cause of death is still unclear, but the police are investigating and do not suspect foul play.
Born on March 7, 1945, in Washington DC, Heard was best known for his role in "Home Alone" and "Home Alone 2: Lost in New York".
He also appeared in some other movies like "Cat People", "After Hours", "Big", "Beaches", "Gladiator", and on TV series like "Miami Vice" and "The Sopranos", for which he won an Emmy nomination for outstanding guest actor.
The actor is survived by two children.