By Anita Oh

COLWYN, PA (CBS) — The District Attorney’s Office of Delaware County has released an image of the suspect they say opened fire on a Colwyn street corner just before 11 p.m. Friday night.

A 20-year-old and a 16-year-old are dead, and a 15-year-old is in critical condition at Penn Presbyterian Medical Center, according to the Delaware County District Attorney’s Office.

“We just heard gunshots, six to seven shots, like ‘Pow pow pow pow,” said David Holloway, who says he was moving into a home a block away when he heard the gunfire erupt.

Holloway says his brother, a field medic, rushed to help one of the young men until first responders arrived.

“He ran out here with his emergency bag and ran straight to the person who had been shot and he said he had been shot in the head,” Holloway said. “When he passed him off and the man got into the ambulance, he was breathing.”

The suspect is seen wearing a white t-shirt with blue jeans, and tan boots.

Neighbors say they’re saddened by the news.

“We’ve got to do better out here. This is crazy,” said neighbor Carla King.

“My heart goes out to the families of the children who passed away last night. I’m going to pray for them,” said Jean Bradley, another neighbor.

Meanwhile, Paul Jones, whose home is across from the shooting scene, says recent violence is part of the reason he’s leaving the neighborhood.

“I put the house on the market today,” Jones said. “It ain’t getting no better here.”

While investigators are still working to identify a motive, they believe some of the young adults traveled into Colwyn from southwest Philadelphia and that this may have been a feud between two rival groups.

Anyone with information is asked to call the Colwyn Police Department at 484-494-4900 or the Delaware County Criminal Investigation Division at 610-891-4700.