MUSCOY - Lurissa Holcomb danced to rap music with her friends in a small shed behind a gray-blue Nolan Street house early Wednesday.

As the 18-year-old Rialto woman turned to head outside into the darkness, her boyfriend spotted a shotgun in the room. What went through his mind at that moment is unclear.

"What we know for certain is that he picked up the shotgun, pumped it, put it up to his shoulder, aimed it at Lurissa and fired it," said San Bernardino County sheriff's Sgt. Frank Bell. "But he said he didn't know it was loaded."

The blast hit Holcomb in her neck and shoulder area and she collapsed. Her boyfriend, Craig Luke, ran to Holcomb and moved her to a driveway where she died.

Deputies arrested Luke, 20, of Redlands on suspicion of homicide. A neighbor, Devin Berry, 20, of Muscoy was arrested on suspicion of accessory after the fact, according to sheriff's officials and booking records.

Both were booked into Central Detention Center in San Bernardino.

Holcomb, a San Gorgonio High School graduate, was hanging out with six friends in what was described as a recording studio near the corner of Nolan and California streets. They said she and her boyfriend were "play fighting" when he grabbed the shotgun.

Jasmine Mays, Holcomb's friend, said Holcomb had either just stepped out of the studio or was preparing to exit when she was shot.

"It was so crazy because it happened so fast," she said. "We didn't think it was a real gun."

Bell said when deputies first arrived at the scene at 2:48 a.m., Luke said there had been a drive-by shooting. He told deputies the shooter was in a black Ford Taurus.

Relatives and friends gathered along California Street while detectives conducted interviews and examined the scene for clues. Luke had been detained by investigators, but was not arrested until early afternoon. He slept in a sheriff's vehicle throughout the morning while detectives combed the scene for evidence.

Holcomb remained uncovered with yellow evidence markers surrounding her body, but deputies eventually placed a black shield in front of her.

Her father, Lewis Holcomb of Highland, described his daughter as an ambitious woman who dreamed of one day becoming a radiologist. She was planning to attend Chaffey Community College in Rancho Cucamonga and was working at Victoria's Secret at Ontario Mills.

But like many teens, she valued independence and moved out of her father's house to live with her siblings in Rialto when she turned 18.

"She just wanted to be grown before her time," he said.

Tensions rose at the scene as family members dealt with the loss and found no clear answers to why Holcomb was shot.

"What kind of friends would do this?" Holcomb's father asked.