DENVER (KDVR) — Police are looking for a suspect after a man was stabbed on an RTD bus Thursday night at Colfax Avenue and Downing Street.

The family of a 22-year-old with autism says he was stabbed 10 times. He survived.

The family is now asking to remain anonymous for now for safety reasons.

“He addressed my brother with, ‘What are you looking at?’ And my brother told him, ‘Nothing,’ you know. ‘I’m not looking at anything.’ So the man got up. I know it evolved around that,” the victim’s brother said.

The family said his facial expressions, brought on by bipolar and schizophrenic conditions, can be misinterpreted.

It’s not clear if that’s what led to the confrontation.

RTD 15L bus route is often a site of violence

The place where the attack happened was one of the routes, the 15L, that was featured in a FOX31 Problem Solvers investigation showing videos of a number of assaults on buses. The route travels along Colfax Avenue.

Thursday night’s victim was on his way home from a tae kwon do class in Arvada and was headed to Aurora. Martial arts are one of his favorite hobbies. His gear was seen strewn about outside the bus.

His family describes him as a young man trying to live on his own, despite his challenges.

“He’s not ashamed of it. It doesn’t stop him. Sometimes, it makes things more complicated,” his brother said.

FOX31 learned the victim tried to get away from the attacker but was stabbed again outside the bus.

RTD is fully cooperating with the Denver Police Department investigation and is keeping the victim of this senseless act in our thoughts. RTD said there was a camera on that bus, and video has been turned over to investigators.

Denver Police said they are now working on putting together a mental description of the attacker.