Minneapolis homicide detectives pressed their investigation of a homicide in the Shingle Creek neighborhood over the weekend, as friends and relatives of the slain man continued to seek answers about the confrontation that claimed his life.

Adding to the tragedy, say those who knew him, was the fact that Kyle Culberson was celebrating his 28th birthday when he died.

Culberson was shot in the chest when gunfire broke out Sunday afternoon during an altercation at a house in the 5100 block of N. James Avenue, according to police and scanner traffic. Two other men suffered gunshot wounds to the legs, but are expected to survive, officials said.

The incident happened shortly after 4 p.m.

Detectives spoke with several witnesses, who gave at times conflicting accounts of what happened: One described the shots coming from a maroon SUV that was seen speeding away before police arrived, while another told detectives that the shooter had on a gray hoodie and fled the scene on foot, according to police scanner traffic.

According to emergency dispatch audio, responding officers found one of the victims in front of the house, another one inside, and the third lying in the backyard, next to a fence.

Officials said the early investigation has produced a number of leads — but, as of Monday night, no arrests — in the slaying, which shook the quiet neighborhood in the city's northwestern corner.

According to a search warrant affidavit, police had been watching the house for months, and had twice raided the property within the past year as part of their investigation. In each of the raids, police seized guns and other evidence from the home, said the affidavit.

Shekinah Thornton said she was lying down for a nap when she heard five to eight gunshots nearby. The nursing assistant said she ran outside to find a man sprawled unresponsive in a neighbor's backyard. She went back inside to retrieve a CPR mask.

She and her mother took turns trying to revive the man, Thornton said, adding that she had a hard time detecting a pulse.

"At that point, I kind of stopped — I could hear his chest had filled up with fluid, and my mom was like, 'He's gone, he's gone,' " she recalled a day later.

Culberson and the other two victims were taken by ambulance to nearby North Memorial Health Hospital in Robbinsdale, where he was pronounced dead a short time later, officials said.

His slaying was the city's ninth homicide of the year.

As news of his death spread on social media, friends and relatives responded with an outpouring of grief.

"Wow I'm so baffled. Happy birthday and rest in heaven," wrote one woman on Facebook. Several commenters described Culberson as a caring person who loved making music and was finding his place in life after numerous brushes with the law.

Others questioned how violence could have broken out on what should have been a joyous occasion.

In the week before his death, Culberson filled his Facebook page with photos of himself in different poses, with captions counting down the days until his birthday.

His last post was at 8:26 p.m. Saturday. "FOUR MORE HOURS!!!!!" it said.

Libor Jany • 612-673-4064 Twitter: @StribJany