A D.C. Superior Court judge on Friday sentenced a Landover man to 20 years in prison for the June shooting death of a coach for a semi-professional Washington football team outside of a D.C. high school.

Judge William M. Jackson sentenced Oma Crawford, 25, in connection with the June shooting death of Ralph Thomas, 36, of Temple Hills. Prosecutors said Crawford brought a .380-caliber, semiautomatic pistol in a gym bag to McKinley Technology High School in the 100 block of T. Street NE. where the D.C. Falcons football team practiced. The two men got into an argument and prosecutors say Crawford , who played for the team, went to his bag and chased Thomas around the parking lot, while firing four shots. Thomas, who was unarmed, was shot in the head.

Crawford pleaded guilty to second-degree murder in July. Crawford told detectives he believed Thomas was having an affair with his wife.

During the sentencing, Assistant U.S. Attorney Todd Gee, said Crawford had a “violent temper” and “needed to grow up behind bars.”

Speaking at the sentencing, several of Thomas’s family members said Crawford planned to kill Thomas, and that’s why he brought the gun to practice. Several family members were angry Crawford was not charged with first-degree murder.

But Crawford’s attorney said her client suffered from a mental illness and “snapped” after an argument.

Crawford said Thomas threatened him. “What I did was cowardly, uncalled for and off emotions,” Crawford told the judge. “I accept complete responsibility. But he threatened me. What I did was monstrous, but I am no monster. I had no intention to kill that man. “