He appeared in a number of successful films, including Heart Beat (1980), Cutter's Way (1981), Cat People (1982), Beaches (1988), and Deceived (1991).

[2] He grew up with two sisters, Lise and Cordis (an actress), and a brother, Matthew Heard, who predeceased his mother and father.

Richard Schickel in Time, David Ansen in Newsweek, and New York City's weekly newspapers would write glowing reviews.

Ansen wrote, "Under Passer's sensitive direction, Heard gives his best film performance: he's funny and abrasive and mad, but you see the self-awareness eating him up inside.".

(Cannibalistic Humanoid Underground Dwellers, 1984) alongside future Home Alone co-star Daniel Stern and in The Trip to Bountiful (1985).

In the comedy-drama film Heaven Help Us (aka, Catholic Boys, 1985), Heard played a monk named Brother Timothy.

He was seen in the film The Milagro Beanfield War and had a significant role playing Paul, Tom Hanks's adult corporate competitor and jilted boyfriend of Elizabeth Perkins, in Big (both 1988).

In 1990 Heard starred in the philosophical film Mindwalk, in which three characters from different sociopolitical and cultural backgrounds express their opinions on the human experience, and around the same time, he was in Awakenings alongside Robert De Niro and Robin Williams, and The End of Innocence with Dyan Cannon.

He starred in Deceived (1991), with Goldie Hawn, playing Jack Saunders, and had a supporting role in Gladiator (1992), with Cuba Gooding Jr.

Heard chose to characterize the role with a combination of concerned dramatic acting of a father missing his son along with more classical comedic tropes.

Heard also had roles on The Sopranos as the troubled corrupt detective Vin Makazian for which he received an Emmy nomination as outstanding guest actor, and later on Battlestar Galactica as Commander Barry Garner.

In 2008, Heard was asked about his career and he replied, I guess I went from being a young leading man to being just kind of a hack actor.

[13] Heard died of cardiac arrest due to atherosclerotic and hypertensive heart disease on July 21, 2017, at the age of 71.

He was found by staff in a hotel in Palo Alto, California, where he was reportedly recovering from minor back surgery which he had just undergone at Stanford University Hospital.