REVERE (CBS) – A young man was shot and killed outside an ice cream shop in Revere late Sunday night.

The 20-year-old man, later identified as Yaseen Butt of Revere, was shot in front of Twist and Shake on Revere Beach Boulevard around 10 p.m. after an “altercation,” according to Massachusetts State Police. They said the shooter ran away.

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WBZ-TV I-Team sources said it appears Butt may have been in an argument with a group of people who chased and beat him before the shooting.

He was rushed to Massachusetts General Hospital in Boston where he died.

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“The investigation into the identity and whereabouts of the shooter is ongoing,” police said in a statement. “No further information is being released.”

Rich Covino said he brings his girlfriend to get ice cream at the Twist and Shake every Sunday. They arrived around 9:30 p.m. and turned right around.

“I know when there’s negative energy in the air,” he said. “I just got a bad feeling and I says honey, we’ll get some ice cream tomorrow.”

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“My heart goes out to the family. I got a 19-year-old daughter, I’m a nurse, so these things touch home,” Revere City Councilor George Rotondo told WBZ Monday. “It’s just sad that took place and I hope whoever did this turns themselves in. I hope they’re apprehended and that justice is served.”