A white police officer who shot an unarmed, black teenager in the bathroom of his New York City apartment is expected to offer his first public account of the slaying on Friday at his department disciplinary trial.

Officer Richard Haste initially faced a criminal manslaughter charge in the 2012 death of 18-year-old Ramarley Graham, which became another flashpoint for outrage over police use of deadly force against black men.

But the criminal case was dismissed because of a procedural error and a new grand jury declined to indict. Federal prosecutors also declined to bring charges, saying there was no evidence to refute Haste’s claim that he shot the teen because he mistakenly believed he was reaching for a gun.

The New York Police Department began public hearings before an administrative judge Monday to help determine whether Haste should be fired, or face some lesser punishment, for the killing. Haste’s lawyers said he will testify Friday.

The shooting stemmed from an investigation of drug dealing in Graham’s Bronx neighborhood.

A narcotics team had a neighborhood convenience store under surveillance. When Graham exited the shop with friends, investigators reported over their radios that they thought they saw a gun in the waistband of his pants.

Haste and his partner tailed Graham home and broke down the door of the apartment where he lived with his grandmother.

The teen ducked into a bathroom. Haste said he fired when Graham reached into his waistband.

No gun was found, but a bag of marijuana was floating in the toilet.

In opening statements at the disciplinary trial, New York Police Department lawyer Beth Douglas told the judge that Haste should be fired for not following department policy. Once Graham ran into his home and locked the door, she said, the officer should have called for backup and waited for instructions from a sergeant.

Haste’s attorney, Stuart London, called him a “hero officer who was attempting to take a weapon off the street.”

An administrative judge will recommend a punishment that would still need approval from the police commissioner.

(AP)