Trial underway for Hatfield man who fatally shot party guest in head

He called 911 after: 'I just shot a guy'

Jim Melwert
May 21, 2018 - 1:59 pm
Derrick Cosby

Montgomery County District Attorney's Office


HATFIELD, Pa. (KYW Newsradio) — The trial is underway for a Montgomery County man who shot a guest at a party he was hosting last summer.

Prosecutors are calling the incident an “execution,” but the defense says it was justified self-defense.

Derrick Cosby, 43, was charged with voluntary manslaughter for the shooting death of 31-year-old Jeremy Chasteen.

In July 2017, Cosby was hosting a party at his home on the 2400 block of East Orvilla Road.

Chasteen was a guest at the party along with his wife and six children. 

According to charging documents, Chasteen started arguing with his wife at the party.

Defense attorney Ed Galang says party-goers will testify the 6-foot, 315 pound Chasteen was physically assaulting his wife.

According to Galang, one witness will testify Chasteen’s wife’s face was changing color because her husband’s hands were around her neck.

That’s when, according to the charging papers, Cosby went upstairs and loaded his gun. As other guests were trying to block Chasteen from his wife, Cosby said he pulled the weapon and shot Chasteen once in the head.

Galang says Chasteen had been asked to leave, but came back in without permission, he says Chasteen being in Cosby’s home without permission is a “big factor” as in Cosby being allowed to use deadly force.

Following the shooting, Cosby called 911 to report the incident, and told the 911 operator, “There was a domestic violence case in my house and I just shot a guy.” 

Cosby would go on to say, “He was beating up his wife and I had no choice.”

The defense says Cosby cooperated with law enforcement — he’s a veteran of the Navy, they noted — and has never been in trouble before.

Prosecutor Richard Bradbury told the jury Derrick Cosby “executed” Jeremy Chasteen.

Bradbury explained to the jury that Cosby went into his bedroom, loaded his handgun, walked back to his family room, and -- in Bradbury’s words - without warning, without notice, without Chasteen being aware of it, he shot him in the head.

If convicted, Cosby could face up to 12.5 to 25 years in prison.