Chicago police detective Dante Servin, 46, (left), and 22-year-old Rekia Boyd (right). (AP and Courtesy Photos)

Chicago police detective Dante Servin, 46, has been declared not guilty of all charges in the slaying of 22-year-old Rekia Boyd with an unregistered firearm.

In March 2012, while Servin was off-duty, he shot a 9 millimeter semi-automatic from his car into an alley where Boyd and her friends were walking, unarmed, with their backs turned.  Of the group, Boyd was the only one to get hit; she died after a bullet entered the left side of her head.  Servin shot his handgun five times, but only one bullet made contact.

Servin told the court that Boyd’s boyfriend, Antonio Cross put a cell phone in the air, which he assumed to be a gun. Servin pulled out his firearm, he said, because he felt threatened after telling Boyd and her three friends to quiet down.

Cook County prosecutors charged the police officer with involuntary manslaughter, reckless conduct and reckless discharge of a firearm in Boyd’s death. But in a directed verdict on April 20, Judge Dennis Porter said prosecutors had failed to make their case.

“Simply put, the evidence presented in this case does not support the charges on which the defendant was indicted and tried,” Judge Dennis Porter said according to ABC7 Chicago. “There being no evidence of recklessness as a matter of law, there is no evidence to which the state could sustain its burden of proof as to the fourth element of the charge of involuntary manslaughter.  Therefore, there is a finding of not guilty on all counts and the defendant is discharged.”

Cook County State’s Attorney Anita Alvarez said in a statement that “justice was denied” for Boyd’s family, according to CBS News.

Servin, who was booed as he left the courthouse, expressed sorrow for Boyd’s family and said her death was an accident. “Any police officer especially would have reacted in the exact same way I reacted,” Servin told reporters.  “I’m glad to be alive. I saved my life that night.”

Since the shooting in 2012, Servin has remained on the police force and he said he plans to return.

“That’s a slap in the face,” Martinez Sutton, Boyd’s brother, told CBS News.