Police officer Mujahid Ramz­ziddin was off duty Wednesday morning, at home on a quiet suburban street in Southern Maryland, when he stepped out to aid a neighbor who had asked for his help.

She was in the process of leaving her husband and the night before had asked the officer to park his marked cruiser in front of her house.

On Wednesday, when he saw her outside removing her belongings, he went over to stand by her and took his police radio and gun with him.

Suddenly, from between a row of homes, the neighbor’s estranged husband emerged carrying a shotgun, police said, and fired five times at Ramzziddin before fleeing with the dead officer’s service weapon.

Police Chief Hank Stawinski said Cpl. Mujahid Ramzziddin, an off-duty Prince George's County officer killed on Feb. 21, had demonstrated heroism before. (WUSA9)

Police had been called in repeatedly for reports of problems at the house. On Wednesday, it was Ramzziddin who intervened.

He was shot dead at about 10:15 a.m., steps from his own house by the man, police said, who had “a history of domestic incidents” in several jurisdictions.

The officer saved the woman as workers at her home Wednesday were changing locks in the aftermath of a violent Valentine’s Day argument with her husband over her plans to break up with him, according to court records and the county police chief.

The veteran officer and father of four “saved her life by giving his own,” said Prince George’s County Police Chief Hank Stawinski.

Ramzziddin’s eldest son said he was not surprised his father died protecting someone else.

“It’s always the good ones who die, isn’t it?” said the son, Eric William Tyler Jr., who spoke from North Carolina as he waited for a sheriff’s deputy to pick him up and take him to Maryland.

The suspect, identified as Glenn Tyndell, fled in a black SUV and was killed by two officers in the Fort Washington area, Stawinski said. When Ramzziddin’s stolen weapon was recovered, shots had been fired from it, the chief said.

Stawinski said a preliminary investigation showed that Tyndell, 37, “should not have had a firearm.” He had three open arrest warrants for assault, police said.

Tyndell, a Metro mechanic, and his wife had argued about the potential split at Valentine’s Day dinner, she told a judge in court filings before being granted a temporary protective order that was still in effect as of Wednesday. The couple was due in court for a hearing next week over claims that Tyndell had been physically violent and had access to firearms and knives.

Tyndell drove to the neighborhood as the locks were being changed, two law enforcement officials said. He was threatening his wife when Ramzziddin stepped in and was fatally shot outside the house in the 15000 block of Chadsey Lane near Chadds Ford Drive, police said.

Ramzziddin, the 30th officer in Prince George’s to die in the line of duty, joined the department in 2004, after three years as a D.C. police officer. The 51-year-old Medal of Valor winner and Marine veteran was most recently assigned to the department’s special operations division.

Maryland Gov. Larry Hogan (R) said in a statement that Ramzziddin “made the ultimate sacrifice in defense of his neighbors and community.”

In remarks Wednesday, State’s Attorney Angela D. Alsobrooks called for a renewed commitment to reducing domestic violence in the county, where she has worked to bring more resources to women seeking shelter and housing aid before they file protective orders.

“A gutless coward took the life of a very important part of the community,” she said at a news briefing.

Of Ramzziddin, she said, “he came out to save a neighbor and died in his own neighborhood.”

Tyndell’s history of domestic violence also included allegations from his ex-wife. She was in court in late January asking for protection for their three young children. She and Tyndell shared custody, and she told the court she was fearful because she was told Tyndell had recently “slammed” his current wife to the ground in front of one of his children.

Her protective order was denied because she “couldn’t meet required burden of proof,” a court spokesman said Wednesday.

Tyndell’s ex-wife declined to comment through her attorney, requesting privacy and time to grieve. His widow could not be reached Wednesday.

Throughout the morning, police cars lined the streets of the Chadds Ford neighborhood while a helicopter flew overhead. Officers from all over the county rushed to the scene. By afternoon, many lined the sidewalks along Chadds Ford Drive in an informal send-off for the fallen officer.

Tyler, Ramzziddin’s son, described his father in an interview Wednesday as a “very honest guy” who pressed the importance of integrity on his children and colleagues.

His father — who converted to Islam in 1997 and changed his name in 1999 — enjoyed coaching young people, in his personal life and on the police force, his son said Wednesday. He never missed his son’s track meets or basketball games.

“He wanted to make young boys into young men,” Tyler said. “And he wanted to make young men into strong men.”

In addition to his wife, Tammi Ramzziddin, and Tyler, Ramzziddin is survived by three more children and two grandchildren.

One neighbor, Earline Harris, said Wednesday that police had visited Tyndell’s home often for domestic disturbances.

“He has gotten into an altercation with a neighbor over some small stuff,” said Harris, a retired D.C. police officer. Harris teared up, thinking about her fallen “brother in blue.”

“My heart goes out to his family,” Harris said. She said she was at work when she heard about the shooting in her neighborhood. She was not surprised.

“I already knew what it entailed,” Harris said.

Another resident of the neighborhood, Gwen Roberts, said she saw news reports of the incident and saw a photo of her house. She looked out her bedroom window and saw police cars and heard a helicopter flying overhead.

She said she was shocked and described the neighborhood as “fairly quiet.”

“I’m right here in the middle of it,” she said. Police tape blocked her husband from coming into the driveway from a morning trip to Costco.

“It’s really a nice neighborhood,” she said. “When the weather’s nice, people are at the pond, people are jogging, walking their dogs.”

In the hours after the shooting, 13-year-old Martrell Johnson recalled the advice he’d gotten from Ramzziddin just the day before. Martrell was collecting money for the American Heart Association. Ramzziddin gave him $10 and a tip — to remember to say his name — to improve his pitch.

He heard about the shooting from his mother.

“Yesterday, I’m talking to the man, he’s fully alive, and then my mom tells me . . .” Martrell said, his voice trailing off. “That’s how crazy — that’s how fast your life can end.”

Jennifer Jenkins, Dana Hedgpeth, Ellie Silverman, Rachel Chason and Ovetta Wiggins contributed to this report.