father of three shot to death on a Brooklyn subway train Sunday night was breaking up a fight when he was killed — as his grieving family called him a man who “always wanted peace.”

Richard Henderson, 45, of Crown Heights, had apparently intervened in a dispute over loud music between his killer and another man before he caught two bullets — one in the back and another in the shoulder — on the Manhattan-bound 3 train at about 8:15 p.m., police and sources said.

“He’s a good man,” his wife, Jakeba Dockery, told The Post. “He didn’t deserve it. Not that.”

Shattered family members gathered Monday at the Brooklyn home of Henderson’s in-laws, where they described the slain man as someone who loved helping others and always put his family first.