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A U.S. soldier suspected of killing 16 Afghan villagers comes from one of the largest military installations in the United States -- and one that has seen its share of controversy and violence.

Joint Base Lewis-McChord in Washington state, home to about 100,000 military and civilian personnel, was the home of four soldiers convicted in the deliberate thrill killings of three Afghan civilians in 2010.

The military newspaper Stars and Stripes called Lewis-McChord "the most troubled base in the military" that year.

Catherine Caruso, a spokeswoman for Lewis-McChord, said she could not comment on reports that the soldier involved in Sunday's shootings was based there. A U.S. official speaking on the condition of anonymity told The Associated Press that the shooter was a conventional soldier assigned to support a special operations unit of either Green Berets or Navy SEALs engaged in a village stability operation in Afghanistan.

It wasn't immediately clear if the soldier was with Lewis-McChord's 3rd Brigade, 2nd Infantry Division, which sent about 2,500 soldiers to Afghanistan in December for a yearlong deployment. The brigade had deployed to Iraq three times since 2003; this is its first deployment to Afghanistan.

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"It's another blow to this community," said Spc. Jared Richardson of the shootings as he stood outside a barbershop near the base Sunday. "This is definitely something we don't need."

The base has suffered a spate of suicides among soldiers back from war. A former soldier shot and injured a Utah police officer in 2010, and on Jan. 1 a 24-year-old Iraq War veteran shot and killed a Mount Rainier National Park ranger before succumbing to the cold and drowning in a creek.

Lewis-McChord has grown quickly since the Sept. 11, 2001, terror attacks. Officials there have said that any community of its size is bound to have its problems, and its reputation has been tarred by "a small number of highly visible but isolated episodes."

In 2010, a dozen soldiers from the base were arrested on a slew of charges that included using drugs, beating up a whistleblower in the unit and deliberately killing three Afghan civilians during patrols in Kandahar province. Four were convicted in the killings.

After the first killing, the father of one of the soldiers called Lewis-McChord to report it -- and to say that more killings were planned. The staff sergeant who took the call didn't report it to anyone else, saying he didn't have the authority to begin an investigation in a war zone. By the time the suspects were arrested months later, two more civilians were dead.

Army Staff Sgt. Calvin Gibbs, the highest ranking defendant, was sentenced to life in prison. At his court martial, Gibbs acknowledged cutting fingers off corpses and yanking out a victim's tooth to keep as war trophies, "like keeping the antlers off a deer you'd shoot."

Richardson said the vast majority of the soldiers at the base were professionals.

"I promise you, not even a percent of those people are like this, but unfortunately it keeps happening," he said. "Things like this will continue until there is no more war. "

Last year, Lewis-McChord saw more suicides than ever before -- 12, up from 9 in each of the prior two years. The Army has seen more suicides at bases across the U.S. since the wars in Iraq and Afghanistan began.

The toll at Lewis-McChord rose despite new efforts to counsel soldiers when they come home from war.

But in the past five years, about 300 patients at the base's Madigan Army Medical Center had their diagnoses of post-traumatic stress disorder reversed by a forensic psychiatry team, The Seattle Times newspaper reported this month. The Army is reviewing whether those doctors were influenced by how much a PTSD diagnosis can cost, in terms of a pension and other benefits.