(CNN) -- A California man pleaded no contest to voluntary manslaughter with the use of a gun Tuesday in the shooting death of a man who he claimed sexually abused him as a teen, a prosecutor said.

The plea comes less than a week before Aaron Vargas' first-degree murder trial was supposed to start for the slaying of Darrell McNeill, a neighbor from his childhood and a family friend whom Vargas claims began molesting him when he was 11 years old.

Under the terms of a plea deal, Vargas, now 32, faces anywhere from probation to 10 years in prison for shooting the former Boy Scout leader and local businessman last year in his home in the Northern California community of Fort Bragg.

Lawyers will return to court April 20 to place a statement of facts on the record before Judge Ronald Brown decides on the final sentence.

"There's some relief that we know we won't lose him for the rest of his life, but there's also a lot of anxiety about what the judge is going to do," said Vargas' sister, Mindy Galliani.

"I won't have closure until he's home," she added. "But even when he's home, it's still not going to be closure. We need to get him into treatment so he can get help. I feel like this is only the beginning."

Since his arrest, Vargas' family has waged a tireless campaign to reduce the charges and raise awareness over child sex abuse, earning support from members of the community and giving rise to more sex abuse allegations against McNeill.

McNeill used his position as a Boy Scout troop leader and as active neighborhood father to win the trust of Vargas and other young boys, Galliani said. He took the boys on camping trips or hikes, gave them alcohol or drugs and molested them, Galliani alleged.

The alleged sexual abuse waned as Vargas grew into adulthood, but McNeill continued to call him and visit the home where Vargas lived with his wife and infant daughter. The continued contact drove Vargas to the breaking point, his sister said.

Vargas was under the influence of alcohol the night of February 8, 2009, when he drove to McNeill's mobile home with a loaded gun and shot him in front of his wife, Mendocino County Assistant District Attorney Elizabeth Norman said.

The prosecutor said she consulted with the victim's family and reached what they thought a jury may have found -- that his level of intoxication placed the crime more along the lines of an "emotional decision rather than an intentional first-degree murder."

Norman said she has received four reports of sexual abuse involving McNeill, which factored into the decision to strike a plea deal even though she could not prove they were true.

"When you have other victims coming forward, that does lend credibility to that scenario," she said. "These people have written me letters and said this has happened, and I have no way of showing this has happened, but it has been put out there."

The slaying victim's wife, who lived next door to Vargas' family and has known the defendant since he was a child, said she had no reason to doubt his claims of abuse.

"I love this young man and feel he needs counseling more than anything," McNeill's wife said in an e-mail. She requested that her name not be published.

"I cannot condone what Aaron has done, but I do understand it. I believe he took the wrong avenue by taking the law into his own hands. Like most of this community, I do not feel he deserves 50 years in prison. Unlike most of this community, I feel he should serve some time, but not much."

The case, with its suggestions of long-buried secrets, has rocked Fort Bragg, a former logging community that has become a coastal tourist destination. Another longtime Fort Bragg resident has come out publicly with allegations of abuse against McNeill.

"I was a reserved kid, some considered me a loner; I just kind of kept to myself as a kid, and he would play on that," Todd Rowan said in an interview in March. "He'd give me pot and beer, and he'd get me stoned and a little drunk, and he took advantage of me that way."

Rowan said the abuse began when he was 15 and continued on and off until he was 19, but the emotional trauma lingered for years, driving him to substance abuse and suicide attempts. He said he brought the allegations to Fort Bragg Police in 2001 but nothing happened.

"All those years, I wanted to forget about and push it away with alcohol because you're supposed to be a man. And then, when police didn't do anything, that pushed me even further down the hole."

Repeated calls for comment to the Fort Bragg Police Department and the Mendocino Sheriff, which handled the investigation of McNeill's death, were not returned.

Rowan said his ability to stay sober for more than two years braced him for news of McNeill's death.

"When I got news that he'd been shot, the first thing I thought was, 'who got him? Somebody got him. Who else did he do it to?'"

McNeill's second wife, Jenny Cotila, who divorced him in 1980, said she also went to Fort Bragg Police in the 1990s after she was told that her ex-husband had sexually abused her son years ago.

"It could've been stopped a long time ago but the police didn't take me seriously when I reported it because they said the statute of limitations was up by the time I found out what happened to my son," Cotila said in a phone interview Tuesday.

Cotila said she has long felt indifference toward her ex-husband but worried about the effects of his death and the abuse allegations were having on their children, now adults.

"It's hard for them to cope because they're friends with Aaron, they knew him," said Cotila. "Darrell's their father and he's their friend. They're having a hard time separating their father from the pedophile."

Members of the community also expressed shock that a "normal" guy like McNeill, a small business owner who installed the blinds in your home after you bought them at his furniture store, was capable of such horrific acts right under their noses.

"Here we have this man, and he's being the normal, small-town businessman, and he's following all the cultural paths available and all the norms, so when you have people coming forward and saying this man is doing something to me that's outside the norm, there's a tendency to not listen closely or to ignore it," said Jeff Edwards, a hospital employee who has lived in Fort Bragg most of his life.

"I guess we are to blame in a way, for thinking that this could never happen in our town."