A teenager has been sentenced to a 10-year prison term for a gang-related murder outside a party bus that was unloading passengers at an Inver Grove Heights parking lot.

Trashaun N. Morris, 18, of St. Paul, was sentenced Monday in Dakota County District Court after pleading guilty to second-degree murder for killing 19-year-old Billy Ray Robles on March 24, 2018, outside the AMC Inver Grove 16 movie theater just off Hwy. 52 and south of Interstate 494.

With credit for time in jail since his arrest, Morris will serve slightly more than six years in prison and the balance on supervised release.

Forty to 50 passengers had gotten off the bus after a rolling birthday party when the shooting occurred. Police said numerous passengers were intoxicated.

The bus with a pink paint job, owned by Safeway Transit in Farmington, was rented by a woman for a birthday party for her younger sister, police said. Passengers ranged in age from 16 to the mid-20s. The company’s website notes that no one under 21 is allowed to consume alcohol on board.

Three others, also teenagers at the time of the shooting, have pleaded guilty for their roles in the incident and were sentenced.

Maurice Martin and Samson Chu, both of St. Paul, pleaded guilty in juvenile court and were given four-year suspended sentences. Taishawn T. Smith, 18, of Crystal, pleaded guilty in adult court to second-degree riot.

Smith was given a 13-month suspended sentence in September 2018 and put on five years’ probation, but he was killed less than three months later in a gang-related shooting in St. Paul.

According to the charges in the party-bus killing, passengers belonging to the “east side” group and others from a “west side” group argued throughout the trip. Fighting erupted about 1:30 a.m. as the east siders stepped off the bus and were chased through the parking lot by members of the west siders.

Morris and Martin turned and started shooting. Robles, of St. Paul, was hit in the chest. Chu was shot in the ankle. He fell after being shot, pulled a gun and returned fire.

Investigators eventually determined that Morris fired the shot that killed Robles.