Police have arrested a Portland man in the shooting death of his domestic partner last weekend at their home in the city’s Riverton neighborhood.

Anthony Leng, 40, was charged with murder in the death of Sokha Khuon, 36. He was arrested shortly before 9 a.m. Saturday at the Portland police station, where he had voluntarily arrived for questioning.

An autopsy by the Office of Chief Medical Examiner determined that Khuon died from “multiple gunshot wounds” and her death was ruled a homicide, police said.

Khuon, 36, was found dead in her home at 46 Dorothy St. about 10 p.m. last Sunday by Portland police, who were called to the scene by a neighbor who heard gunshots.

Two of the couple’s children, a 10-year-old and a 15-year-old, were home at the time of the shooting. They are being cared for by “supportive” family members and are receiving counseling, Assistant Chief Vern Malloch said during a news conference Saturday morning at the police station.

Earlier in the week, police called Khuon’s death – in a quiet residential neighborhood near Morrill’s Corner and Riverton School – “suspicious,” but released few details about it.

Malloch said the weeklong investigation was complex and involved several police detectives. He said police knew where Leng was throughout the week and were confident he posed no danger to the public.

Malloch said the two children who were home fled to safety and were outside the house when police arrived Sunday night. Investigators at the time would not discuss whether Leng was home that night. Malloch did not say whether the children witnessed the killing of their mother.

Malloch said a handgun was used in the shooting but did not say whether police recovered it.

He said Leng had no history of domestic violence or other crimes. He also said Khuon’s slaying remains under investigation.

Leng is being held without bail at the Cumberland County Jail pending his appearance Tuesday in Portland District Court.

“Domestic violence is tragic and devastating to family and friends and to all of society,” Malloch said.

Neighbors of the couple, who described them as quiet and family-oriented, said they were perplexed by the shooting.

Neighbors said Leng is outgoing and seems to enjoy helping neighbors. They said he likes to fish and hunt and owns firearms.

Khuon, a native of Thailand and a 2000 graduate of Portland High School, worked at Direct Mail Maine. Leng is an assistant maintenance technician for the Portland Housing Authority, where he has been employed since 2006. He was placed on administrative leave, Mark Adelson, executive director of the housing authority, said in an email Tuesday to PHA commissioners.

“We’re in shock that something like this could happen,” Adelson said in the email. “We don’t know any of the circumstances. You don’t believe it can happen here until it does.”

Adelson told the Maine Sunday Telegram on Saturday that Leng called his supervisor after the shooting.

“Anthony had called and said he wouldn’t be in to work, and that there had been a shooting at his home,” Adelson said. “When he didn’t return to work, we put him on administrative leave.”

Adelson described Leng as “a steady worker” with good skills who seemed to get along with everyone.

In Khuon’s obituary Saturday in the Portland Press Herald, her family described her as sweet and outgoing with a great sense of humor. They said she liked to spend time with her children, friends and family, as well as to garden, fish and cook new recipes.

She is survived by her children, Myra, 18; Anferni, 15; and Kaidan, 10; her mother, Pov Phach; and several siblings, her obituary said.

Staff Writer J. Craig Anderson contributed to this report.

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