'It was just anarchy. A rampage': Victim recalls being attacked by more than a dozen teens on light rail train

Oct. 14 was a typical Friday afternoon for Zachary Chopko. He hopped on the light rail to head back to work after his lunch break. 

"It was just supposed to be a quick thing you know just jump on the light rail, it's one stop," said Chopko, of Lakewood. 

When he boarded the RTD eastbound W line at the Garrison station, he noticed the only other passengers were a group of teens. Listening to music, he didn't acknowledge them, but out of the blue, they attacked.

"I got on, I got hit in the back of the head and they just started beating me," said Chopko. 

Punching and kicking Chopko, the teens screamed profanities. The violent attack was caught on video and shared with CBS News Colorado. 

"I was being pushed, I was being hit, I don't know," said Chopko. "It was just anarchy. A rampage. Just horrible." 

Chopko somehow stumbled out of the train and flagged down a police officer, but the kids were already gone. He rushed to the hospital, where he learned the extent of his injuries.

"Concussions, ribs, stitches in my eyes, my face, my ears, everything was messed up," said Chopko. 

But as Chopko began his recovery, the group appeared to strike again. On Nov. 3, a 47-year-old man was assaulted by a group of teens on another light rail train. According to the district attorney's office, the victim broke several bones and required facial reconstruction surgery. 

"This is not the only incident. I mean, it happened more than once," said Chopko, "It makes you look at the world differently."

Now Chopko is angry, traumatized and asking why.

"This is past kids," said Chopko. "This is adult behavior. It's primitive behavior, it's something adults shouldn't be doing."

The Jefferson County District Attorney's Office has arrested 13 teenagers between the ages of 15 and 17 for assault. Nine are charged in Chopko's case and seven in that second attack weeks later. There are three teens who allegedly took part in both attacks. All involved teenagers are currently being charged as juveniles.