A DeKalb County man was sentenced to life in prison for a 2019 rampage in which he fatally shot his girlfriend, then ambushed responding officers and shot one of them before escaping, prosecutors said Wednesday.

Otis Dennis Walker, 32, of Lithonia, was on the run for nearly a week before he was taken into custody Aug. 8, 2019, police said. A jury found him guilty Sept. 27 of killing his girlfriend, 27-year-old Aleka Simmons, and shooting police Officer Derek Nunn four times, DeKalb District Attorney Shery Boston said in a statement.

Superior Court Judge Yolanda Parker-Smith handed down the life sentence, which included an additional 65 years to be served consecutively, the DA’s office said.

Walker had a history of domestic abuse, police said at a news conference when he was captured. Less than a month before the shootings, Walker had been arrested in connection with another domestic incident and charged with battery, jail records show.

According to Boston, 911 operators received multiple hangup calls from the home where Simmons and Walker were living on Hodgdon Corners Cove on the night of the shooting. During one of the calls, an operator heard the caller say, “This is Aleka Simmons ... If anything happens to me ...”

The statement was followed by arguing in the background before the caller could be heard asking, “Are you threatening me? Are you going to kill me?”

Nunn responded to the home after that call but left when he found the home dark and quiet, Boston said.

Walker’s mother and two children were also staying in the house at the time, according to Boston. She was sleeping when one of the children knocked on her door and told her police were outside. Walker’s mother went to the bedroom he shared with Simmons and offered to give Simmons a ride somewhere, but Walker told his mother that his girlfriend intended to speak to the officers and shut the bedroom door.

Moments later, Walker’s mother heard a gunshot, Boston said. She went back to her son’s bedroom and saw that Simmons was wounded. Walker told his mother he did not want to go back to jail.

Walker’s mother then fled to a neighbor’s house with the children and called 911.

Nunn responded to the house again with two other officers. As they approached, Walker unleashed a barrage of gunfire at them, hitting Nunn several times. Walker fired 19 shots before running into the woods.

A SWAT unit responded and found Simmons dead in the bedroom with a gunshot wound to her chest, Boston said. Nunn was taken to Grady Memorial Hospital, where he underwent emergency surgery before staying at the hospital for about a week.

Multiple agencies conducted a manhunt for Walker until a tip led investigators to a hideout in the Lithonia area, police said. When Walker was arrested, he was carrying a signed letter of apology addressed to Nunn and the DeKalb Police Department, Boston said.

Boston said Walker argued at trial that he acted in self-defense when he shot at police. He also claimed he only shot at the ground in an attempt to provoke the officers into shooting him.

He was found guilty on counts of malice murder, felony murder and aggravated assault, as well as three counts of aggravated assault on a law enforcement officer and a gun charge.