WELLESLEY, Mass. — The widow of a cardiac surgeon gunned down at a Boston hospital told hundreds of people at his funeral Friday that he was well liked by his patients and it was difficult to believe his death came at the hands of a patient’s son.

The service for Dr. Michael Davidson was held at Temple Beth Elohim in suburban Wellesley, where he lived with his wife and three children, ages 9, 7 and 2.

Boston police said Davidson was shot Tuesday morning at Brigham and Women’s Hospital by Stephen Pasceri, who then killed himself. Pasceri’s sister and brother have said he may have held Davidson responsible for the death of their mother from heart and lung problems in November.

The doctor’s wife, plastic surgeon Terri Halperin, said the fact a patient’s family member “would take Michael away from us makes it all the more devastating.”

“Michael received letters and gifts often from patients and their families, thanking him for his care and for all of the time he spent with them,” said Halperin, who’s pregnant with the couple’s fourth child.

Davidson’s father, cardiologist Robert Davidson, was among other relatives and colleagues to speak at the service. He said he and his wife had been hopeful on their flight from California that their son would live.

“When he was young, he said he wanted to follow in my footsteps,” said Davidson, who works at Cedars-Sinai Medical Center in Los Angeles. “But wherever I walked, he ran.”

His wife, Susan Davidson, added, “My heart is broken, and only Michael can fix it.”