A teenage boy has been arrested on suspicion of murder in the party bus melee that left a 19-year-old man dead and two others injured outside an Inver Grove Heights movie theater complex over the weekend, authorities said Tuesday.

In the meantime, police said, the bus company will come under scrutiny to determine whether it carried out its responsibilities to keep its patrons safe.

The 16-year-old suspect from Hopkins arrived at police headquarters late Monday with one of his parents, was questioned and apprehended in connection with the late-night shooting of Billy Ray Robles, an aspiring rapper from St. Paul, police said. The teen, booked on suspicion of second-degree murder, has yet to be charged.

At least one other individual, described as “a person of interest,” is being sought for questioning, Police Chief Paul Schnell said.

Schnell said that law enforcement’s “investigation remains in the early stages. These investigations are complex given the range of evidence that will require forensic testing and the witnesses [that] investigators still need to locate and interview.”

The chaotic scene erupted about 1:30 a.m. outside the AMC Inver Grove 16 theaters just off Hwy. 52 and south of Interstate 494, where the bus was letting off the 40 to 50 passengers after a rolling birthday party celebration.

While a specific motive for the violence has yet to be determined, the police statement announcing the arrest said “rival gang affiliation” between two groups of males could be behind the clash. Robles was shot in the chest.

Another man who was on the bus was punched in the face and taken to Regions Hospital. Police discovered a 16-year-old boy shot in the leg when a speeding vehicle was pulled over about 5 miles north of the theater. Emergency dispatch audio disclosed that the teen had a stun gun in his possession.

A number of people “were quite intoxicated,” the chief said. “Alcohol was certainly a factor.”

Schnell said that once the murder investigation winds down, police will turn its attention to the bus company’s obligations to the well-being of its passengers.

“We’ll certainly look at other kinds of considerations,” he said, “who provided the alcohol and those type of things.”

The bus, painted a festive shade of pink, is owned by Safety Transit in Farmington and is rented via rentmypartybus.com, which lists a Minneapolis address on its website. Messages were left with the company seeking information about its safety precautions and rules about drinking.

The company’s website notes that it has a “zero tolerance compliance policy” addressing passenger behavior, including that no one under 21 years old can consume alcohol on board.

The policy also says the company “will not be responsible for anyone’s actions on or off the bus or for injuries that may occur while the vehicle” is moving or parked. Ultimately, the person contracting for the bus “is responsible for his or her guests,” the policy continues.

The patrons, most of them females, boarded the bus in the theater parking lot between 10 and 11 p.m. Friday and made stops in Minneapolis and Hastings as part of a birthday party gift from a woman to her younger sister, Schnell said.

The passengers were mostly from St. Paul, West St. Paul and Inver Grove Heights, and of various ethnic backgrounds, Schnell said.

Anyone with information about this case is urged to contact police at 651-450-2525.