Left: Austin Doucette (Franklin County Sheriff's Office). Right: Mikayla Rose DeSantis (GoFundMe).

A man in Maine is behind bars after killing his girlfriend in a barrage of gunfire, according to law enforcement in the Pine Tree State.

Austin Doucette, 24, stands accused of murder over the death of 23-year-old Mikayla Rose DeSantis, according to the Maine State Police.

The incident occurred at the Left Bank condominiums in Carrabassett Valley – a tiny town located some 120 miles north of Portland.

A 911 call was placed around 7:30 p.m. on Sunday, according to law enforcement. The Franklin County Regional Communications Center fielded the report about the shooting and state police responded.

Paramedics met DeSantis and Doucette along Route 27 and found her suffering from multiple gunshot wounds. She was rushed to nearby MaineHealth Franklin Hospital in Farmington. The victim was then taken in a helicopter to Maine Medical Center in Portland, where she died from her injuries.

The defendant himself made the emergency call, according to court documents obtained by Portland-based CBS affiliate WGME. Police described Doucette as "very hysterical throughout the phone call as he was yelling and shouting."

"I can't believe I did this," the caller said at one point, police claim. Then, Doucette allegedly told the dying woman: "I'm sorry babe."

The caller also mentioned a gun and said it had accidentally gone off, according to law enforcement. After that, the defendant allegedly told the dispatcher he was leaving with the victim to obtain aid.

Moments later, the first call terminated, law enforcement said. Then, a few minutes after that, the man called 911 again.

"My girlfriend has a gunshot wound," the caller told the dispatcher during the second call, adding: "It accidentally went off."

The narrative of an accident appeared consistent in both calls.

The defendant identified the victim by her first name and said she had been shot in the "stomach/abdomen area," according to police.

"I would never do this," he allegedly told the dispatcher later on in the second call before adding, "I don't want to go to jail."

When law enforcement first arrived at the residence, Doucette was speeding away from the scene of the crime, according to police. He was arrested during a traffic stop the night after the shooting.

Both the slain woman and the defendant worked together at the Sugarloaf Mountain ski resort. They hailed from Connecticut.

Meanwhile, detectives also reviewed another 911 call made by Doucette's father's girlfriend.

During the call, the woman allegedly said she heard the defendant reveal he was being chased by the cops, that something had happened to DeSantis, and that he was going to kill himself. Doucette's father told him not to do it, the woman said, before hanging up upon learning that the defendant had been stopped by police while she was on the line.

Inside the defendant's car, Carrabassett Valley police officers found reddish brown stains in the back seat, along with a receipt and a cellphone, according to law enforcement. Doucette later said the phone likely belonged to DeSantis.

During a custodial interview with state police, the defendant said the victim was his girlfriend, reiterated his claim that the violence was accidental, and told police the gun involved in the shooting was still on the couch in the condo, according to charging documents obtained by Bangor-based CBS affiliate WABI. But then, Doucette invoked his right to remain silent until conferring with an attorney, police say.

A paramedic later told detectives about the original meeting with the couple, saying the boyfriend described a .45-caliber gun going off, according to an affidavit obtained by WABI.

At the second hospital, a state police detective told another investigator that DeSantis was in surgery for what appeared to be a gunshot wound to the chest, but that she had lost a lot of blood and that she was unlikely to survive, according to the affidavit. Later, the Office of the Chief Medical Examiner performed an autopsy and ruled that DeSantis's death was caused by multiple gunshot wounds, police said.

On Monday, a search warrant was executed at the defendant's condo, where multiple shell casings of Blazer .45 auto ammunition were recovered, authorities said. As the defendant allegedly said, the gun was on the couch, with a magazine and unspent ammunition nearby.

"This appears to be a terrible accident and we hope to get more information in the near future regarding the circumstances of the situation," said Doucette's attorney, Verne E. Paradie, in a statement to Maine's Total Coverage.

A GoFundMe started by the victim's brother remembers her fondly.

"Makayla was the most heartfelt, well-minded woman I've ever been around," the fundraiser reads. "She was the best big sister and the greatest role model I could've asked for, and was the most loving girl, who loved to bake for her loved ones, loved to do crafts in her free time, loved to paint, and enjoyed going to work every day and being around people who supported her and loved her for who she was."

The victim and her alleged killer had been together for well over seven – nearly eight – years, according to her brother.