The man charged this week with killing a good Samaritan in north Minneapolis will remain in jail without bail because of a probation violation and a previous assault charge.

Devon D. Parker, 20, quietly answered a judge’s questions Tuesday during a short hearing in Hennepin County District Court. Nearly 20 of his relatives and friends crowded into the courtroom.

Thomas Sonnenberg, 69, was shot to death with his own gun by Parker, according to second-degree murder charges filed Monday. On Friday, Parker knocked on Sonnenberg’s door at his house in the 3700 block of Aldrich Avenue N. and said someone was chasing him. Sonnenberg let Parker inside, and moments later, for reasons unknown, Parker shot him, according to court documents.

Parker, of Minneapolis, had been acting strangely in several recent incidents with family and police, the documents said. In separate incidents, he jumped from his girlfriend’s moving car, kicked police officers who showed up to take him to detox, punched his mother and shot at a bus after the driver confronted him for not paying, the documents said.

On Tuesday, Judge Robert Small mentioned probation violations and the conviction for assault on the bus driver as the reasons why Parker was being held without bail. The prosecution is asking for $2 million bail in the death of Sonnenberg, but Parker’s attorney said she will reserve discussion about the amount until a later date.

Parker’s mother declined to comment after the hearing. He will be sentenced for the probation violation and bus driver assault on Feb. 13.