Updated Jan. 18: Revised to include details from Wednesday news conference.

Little Elm's police chief provided more details Wednesday about the fatal shooting of a detective the day before, but the gunman's name has not yet been released.

Detective Jerry Walker (Little Elm Police Department)

Detective Jerry Walker was shot during a standoff with a barricaded man in the 1400 block of Turtle Cove Drive that lasted for hours and forced dozens of neighbors to evacuate. He died at a Denton hospital Tuesday night.

The suspect was found dead in the home shortly after 10 p.m.; his cause of death has not been released.

Walker, 48, was an 18-year veteran of the force. He was promoted to detective in 2013.

"He was a model officer and a person who will be missed here at the department and in the town of Little Elm," police Chief Rodney Harrison said late Tuesday.

Harrison said Walker had four children ranging in age from 22 to a few months.

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Police responded to the scene around 3:30 p.m. after a passer-by reported seeing a man with a gun.

Patrol officers found an armed man in the backyard, and he retreated into the home after police told him to put down the weapon. At that point, officers called for a SWAT team and started to set up a perimeter around the home, Harrison said at a news conference Wednesday.

Around 4 p.m., the man started shooting through a window or door, and officers fired back.

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Walker was struck in the upper body, and other officers were able to get him to a vehicle and take him away from the scene. He was flown by air ambulance to Medical City Denton, where he later died.

Walker is the first North Texas officer to be fatally shot in the line of duty since the ambush on officers in downtown Dallas on July 7, and the only for the Little Elm Police Department.

Little Elm Police Detective Jerry Walker has passed away. Officers salute as his body is carried out. Bagpipes being played. @ntTV_News pic.twitter.com/r4zpOBflXy — Blake Holland (@tblakeholland) January 18, 2017

Harrison said officers were able to rescue an elderly relative of the shooter from the home through a first-floor window, and he said authorities believed the shooter was alone inside at that point.

Around the same time, the Denton County Sheriff's Office used an armored vehicle to create a hole in the front of the home and send a robot into the house. The robot was able to confirm that the suspect was dead, Harrison said Wednesday.

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Police evacuated residents from nearby homes as the standoff stretched into the night. The city of Little Elm referred to the incident as an active-shooter situation and asked residents to avoid the area.

Several nearby schools held students on campus after classes ended, until police said the area was clear.

1 / 6Little Elm firefighters Xavier Alonzo (left) and Terry Anderson help put up a placard to be signed by those visiting the makeshift memorial outside the Little Elm Police Department for Detective Jerry Walker. (Louis DeLuca/Staff Photographer) 2 / 6Residents place flowers outside the Little Elm Police Department on Wednesday. (Louis DeLuca/Staff Photographer) 3 / 6Roxie Murillo lights a candle with her 4-year-old son, Julian Ruiz, at a memorial for Detective Jerry Walker outside the Little Elm police headquarters. (Jae S. Lee/Staff Photographer) 4 / 6Police officers console each other Tuesday night outside the emergency room at Medical City Denton. ((Jae S. Lee / Staff Photographer)) 5 / 6People leave the emergency room at Medical City Denton. (Jae S. Lee/Staff Photographer) 6 / 6Police officers and firefighters salute as the body of Little Elm police Det. Jerry Walker leaves Medical City Denton. (Jae S. Lee/Staff Photographer)

Chris Baggett, one of Walker's friends, said the detective served several years in the Army.

Detective Jerry Walker (via Facebook)

"Most people coming out of the military go from one uniform to the next," said Baggett, who has known Walker for more than a decade.

Baggett said he bonded with Walker over their military service and a mutual love of Jeeps.

When Baggett heard about the standoff in Little Elm, he began texting his buddies in law enforcement. Nobody answered, Baggett said.

He recalled the moment he turned to the TV and heard his friend's name.

"Oh my God," Baggett said. "You've got to be kidding me."

"Blessed are the peacemakers. #weseeyou" sign says outside public safety center in Little Elm. #rip pic.twitter.com/lYEzgupj41 — Eline de Bruijn (@debruijneline) January 18, 2017

Many former students at Little Elm High School remember Walker fondly. He used to be a school resource officer there.

Lionel Valdez met Walker at the school, around the time he stopped talking to his father and began acting out. He said the officer took on a paternal role and made sure Valdez stayed out of trouble, even checking on him in class.

Walker had a way of talking to people that put them at ease, Valdez said. Some kids would arm-wrestle with him during lunch.

"Years after I graduated I continued going up to the school to say hi and thank you to the man who showed me light during dark times in my life," said Valdez, now 30.

Theresa Rocha, Valdez's mom, said she once told Walker he was her angel for watching over her two boys. He was a customer at the Little Elm bank where she works, and she would often give him updates about her sons: how they both had jobs and were good fathers. How grateful she was about his influence.

"He was so happy to hear how well the boys are doing," Rocha said.

Michael King stood in the cold before a memorial in front of the Little Elm Public Safety building. He also met Walker when he was a student at Little Elm High School.

"He guided everybody on the right path, or he tried to," King said. "He meant well."

Michael King, a former Little Elm High School student, stands in front of a memorial for slain Detective Jerry Walker. ((Eline de Bruijn / Staff))

King said Walker would come by the Sonic drive-in where he was a manager to try to persuade him to join the police force. King finally gave in. He's in the process of joining the police academy in Collin County, he said.

"I'm not just doing this for me anymore; I'm doing this for him," King said. "He's going to be missed."

King gave some cash to friends heading to the store to buy candles for an impromptu service in front of the building.

"Tell everybody that man is an awesome man," King said. "He saw past the bad in everybody. He only saw good."

Brad Sutton, a pastor at Point Church, said his wife could hear the gunshots when the standoff began.

"We have to remind one another that we are neighbors, that we love one another and that these guys love them," he said at the makeshift memorial late Monday. "Man, our cops love this community, they love serving here, they really do."

A candlelight vigil to honor Walker is planned for 7 p.m. Wednesday at Little Elm Park.

Staff writers Eline de Bruijn and Naheed Rajwani contributed to this report.