"He was a good kid gone bad," Cooper said.
The elder Richardson used to mow grass at Aberdeen Proving Ground, family members said. He had recently been living on disability benefits. He took it very hard when Bear's mother died five or six years ago of cancer, Will Richardson said.
"When his wife died, it's like he just climbed inside himself and just shut down," he said. "He wasn't quite right after that."
Richardson called one of his half-sisters after he allegedly killed his father, according to investigators. She called police.
The sheriff's office has not commented on a possible motive in the killing.
"Our investigation is active and ongoing, and we will not comment on an active and ongoing investigation," spokeswoman Monica Worrell said. "The next step is the trial, and that is when more information will be available to the public."
The Pikesville lawyer hired to represent Richardson, Marc Snyder, also said he couldn't comment in detail.
"I spent hours visiting with my client," Snyder said. "He's an exceptionally intelligent and sensitive young man who's found himself in circumstances no one should be forced to endure. And I look forward to the truth being revealed at the appropriate time."
Harford County State's Attorney Joe Cassilly declined to comment on the case.
Records of calls for service show that police stopped by the home a dozen times last year, including a few times when Richardson ran away.
"When deputies visited the home, there was nothing that indicated or demonstrated child abuse, neglect or domestic disturbances," Worrell said.
The calls for service included several visits to deliver court papers, which could happen for many reasons including traffic violations. Police went to the home in July when Cooper called to say she heard shots fired in the neighborhood behind the home.
Police visited in September when an anonymous person said they smelled marijuana coming from the house. Officers found no evidence.
Richardson had run away from home about a month before the killing, according to police records. His father called police after he didn't come home from school on a Friday. He was found five days later, and told police he had been in the Havre de Grace area.
The teen told officers he didn't want to go home because he thought he was in trouble. A sheriff's deputy wrote on a missing-person form that Richardson had trouble with both law enforcement and at home.
Some of the boy's other relatives say they're grateful for the outpouring of community support.
"I think it's awesome," said Betty Rose, whose daughter is married to the younger Richardson's half-brother from a different father.
Rose and another daughter, Rachel Trinkline, called Richardson a quiet kid who never showed a violent streak. They believe he is innocent of murder and say they have no idea what happened in the household.