The two teenage friends were hanging out in Mayfair around 9 p.m. Monday when they apparently decided to walk to a nearby store to grab a snack.

But suddenly, police said, the teens - ages 14 and 16 - were ambushed on the 6200 block of Brous Avenue by two males wearing hoodies. As the teens tried to run, police said, one of the males opened fire with a semiautomatic handgun, fatally striking the 14-year-old, Ian Wilsey, in the chest.

Homicide Capt. James Clark said Tuesday afternoon that investigators were searching for clues that might help identify the males and their motive. "We don't know if it's a robbery, [or] a prior altercation," Clark said.

Wilsey lived about 21/2 miles from the crime scene, on the 1700 block of Cottman Avenue in Castor. Clark said that Wilsey's friend - whom he did not identify - lived in Mayfair, and that the pair had been hanging out most of the day Monday.

Neighbors around Brous Avenue said Tuesday that they were surprised the area would be the scene of such violence.

"I heard, 'bang, bang, bang,' and my wife said, 'That's gunshots,' " said Efrain Sanchez, 54, who has lived on Brous for more than a year.

Patricia James, 67, who lives around the corner on Devereaux Avenue, said she was in bed when she saw several muzzle flashes and heard gunfire.

Teens sometimes play with firecrackers or dirt bikes in a nearby alleyway, she said, but the sound of the gun - which was "very loud" - was something new.

"It concerned me," James said.

Wilsey was a ninth grader at Northeast High School, the School District said in a statement. Attempts to reach his family Tuesday were unsuccessful. A GoFundMe page was created to assist with his funeral costs.

Clark said detectives were searching for additional witnesses, surveillance video, or any other helpful leads.

Tipsters are asked to call the homicide unit, 215-686-3334. A $20,000 reward is available for information that leads to the arrest and conviction of any homicide suspect.