PORTLAND — The state medical examiner has determined that Allen MacLean, the 41-year-old Portland man killed Monday morning near the corner of Congress Street and Massachusetts Avenue, died from a gunshot wound to the chest.

Witnesses said they heard a loud pop at 4:20 a.m. and saw MacLean running across the street from 4 Massachusetts Ave. yelling “I’m dying. I’m dying.”

“He was just flailing his arms … He almost got hit by a car and then he collapsed on the sidewalk,” said Melissa Broome, who was waiting for her supervisor to open a nearby convenience store where she works.

Broome ran across the street and saw that MacLean was bleeding badly.

“I didn’t know what to do. I don’t have any medical training so I just held his hand and told him the ambulance was coming,” she said.

Police continue to search for the person responsible for the shooting and to determine the circumstances that led to it. Police suspect the shooting happened in an alley outside the three-story apartment building, where a party had been held in the first floor earlier in the evening.

MacLean did not live in the building, police said. Police recovered a gun and other evidence nearby.

Mclean was a longtime Portland resident who his family described as a warm-hearted and loving person, who enjoyed the outdoors.