CHICAGO (CBS) – The mother of a young man killed by a Chicago police officer blasted Police Supt. Eddie Johnson on Monday for ruling the shooting was justified under police policy.

Officer Robert Rialmo fatally shot Quintonio LeGrier, and a bystander, Bettie Jones, at a West Side apartment building in 2015.

“He killed these two people in cold blood,” said LeGrier’s mother, Janet Cooksey. “He’s a thief; he’s a liar, and he’s a murderer.

CBS 2’s Derrick Blakley reports, she’s livid Johnson has ruled that shooting justified.

“Johnson said he wants to regain the public’s trust. He hasn’t done anything to support those words. Nothing.”

For the first time on Monday, Johnson publicly addressed his decision.

“The way I came to that decision was not being pressured by political entities or public entities. It was simply looking at the law, looking at department policy and general orders.”

But an independent board ruled the shooting un-justified.

Shell casings indicated LeGrier, who held a baseball bat, wasn’t close enough to endanger Rialmo. Eyewitnesses interviewed by CBS 2 after the shooting corroborated that evidence

“How can you be a threat if you’re shooting from the sidewalk and he’s in the hallway?” Cooksey said. “He’s too far away from him to ever pose any kind of threat.”

Johnson defended his decision, emphasizing, he’s not the last word.

“The police department doesn’t determine whether a police officer is fired or not. The police board does that, another independent, civilian entity.”

The board and Johnson will now meet to determine if the different conclusions can be resolved.

If that doesn’t happen, one member of the police board will ultimately recommend to the full board whether Rialmo should be fired.