A Staten Island military man was arrested and charged Sunday in the murder of his Air National Guard girlfriend and their two young sons, police announced.

The arrest came as new details emerged about accused killer Shane Walker’s violent past — and his Russian-born girlfriend’s tragic story of achieving her American dream only for her life to be cut short at 37.

Cops charged Walker, 36, with murder, manslaughter, arson and criminal possession of a weapon for killing US Air National Guard Airman 1st Class Alla Ausheva along with the couple’s sons, Ivan, 2, and Elia, 3.

Ausheva was found bludgeoned to death in her home Saturday near the bodies of their children, who appeared to have been drowned.

Police sources revealed Sunday that Ausheva’s supervisor made the gruesome discovery while checking on her after Walker was found wandering the Brooklyn-Queens Expressway carrying her cellphone and military ID early Saturday.

Sources say Walker is a member of the Air Force, although a Department of Defense database only shows him as having served in the Army National Guard from Oct. 26, 2011, to March 9, 2012.

Walker was jealous and had a history of domestic violence, according to sources. He was arrested in December for allegedly hitting Ausheva after she returned from a Dunkin’ Donuts run and he accused her of infidelity, sources said.

“They had a prior domestic where he hit her,” a high-ranking source said.

“He accused her of fooling around on him.”

Ausheva had an order of protection against Walker, and it was in effect at the time of the slayings, the sources said.

Walker now faces 12 counts of murder, three counts of manslaughter, three arson charges and three counts of criminal possession of a weapon for the killing, according to police.

The couple’s Palisade Street home was filled with smoke when Ausheva’s supervisor arrived — but the NYPD still couldn’t say Sunday evening whether the arson charge was related.

It was also unclear what weapon Walker allegedly used.

He was undergoing a psychiatric evaluation at Maimonides Medical Center on Sunday, sources said.

Ausheva came to the United States in 2011 after her then-husband won a green card lottery. It is not clear when they separated.

She joined the Army National Guard the same year she came to the US, and later transferred to the Air National Guard in 2014, according to agency spokesman Col. Richard Goldenberg.

“One year ago, I moved from Russia — that’s when my first dream came true,” Ausheva tells an audience in a 2012 YouTube clip. “Then in [the] summer, I joined US Army — that’s when my second dream came true.”

She was granted citizenship in 2012 during a naturalization ceremony presided over by President Barack Obama.

Ausheva served full-time and was stationed at Fort Hamilton Army Base in Brooklyn, according to the National Guard.

“Our thoughts and prayers are extended to the families of those involved and the military members who served alongside Airman 1st Class Alla Ausheva of Staten Island, NY,” Goldenberg said in a statement