An unarmed Philadelphia man was shot and killed Wednesday night by a plainclothes police officer.

NBC Philadelphia reports cops approached motorist Dennis Plowden after spotting his 2013 Hyundai. The cops, who were undercover at the time, claim the vehicle and license plate were connected to a homicide in the area. When the officers exited their unmarked car and began advancing on the 25-year-old, Plowden sped off. His car hit the cops’ vehicle and allegedly struck one of the officers.

When cops later caught up with Plowden, he’d hit two other nearby cars. The  married father of two took off on foot and cops said he didn’t adhere to instructions to put his hands up. Plowden, who then sat down on the sidewalk, later reached into his pocket. One of the officers, who has yet to be identified, claimed he thought the young man was reaching for a gun and shot him in the head. No weapons were discovered on him.

WHYY Philadelphia reports Plowden was pronounced dead Thursday morning after being transported to a nearby hospital. Cops later discovered he was not a person of interest in the killing that led them to pursue him.

Philadelphia First Deputy Commissioner Myron Patterson said homicide detectives are looking into Plowden’s killing.

“The use of deadly force is the most serious action that any law enforcement officer can do,” Patterson said during a press conference. “We take it very seriously. We want to ensure that a very objective, transparent, and comprehensive investigation is conducted at this particular point.”

His grandmother told the Philadelphia Inquirer the cops’ deadly use of the gun was unnecessary.

“I want justice for my grandson,” Stacy McCoy said. “They [the officers] need to be charged with something. … They didn’t have to shoot my grandson in the head. … They just killed another little black kid, unarmed. That’s the way I see it. It’s horrible.”

Plowden’s wife has created a GoFundMe account for assistance with funeral expenses.