An 18-year-old has been arrested in the shooting death of a fellow teenager, the Sacramento County Sheriff's Department said Monday.

Mario Andreas Contreras was taken to the Sacramento County Main Jail and booked on a murder charge, according to a news release. He's held without the option to post bond.

Watch report: Orangevale neighborhood in shock after teen is gunned down

Erik Glen Ozee, 16, was shot to death Sunday night in Orangevale, deputies said.

Even though deputies have made an arrest, they are still exploring exactly what led to the shooting.

"Was this a party interrupted? Being a group of people already at the residence with the victim, and another group with the suspect, was this a crashing of a party?" said Sgt. Lisa Bowman, referring to the questions that detectives are asking.

Officials were called to the 5600 block of Skyridge Drive after someone reported hearing gunshots in the area.

Neighbor Liz Olsen said she heard six shots. "Five rapid ones and one, just final, one," Olsen said. "And I thought, 'I'm not going outside. There could be retaliation.'"

When deputies arrived, they found Ozee with at least one gunshot wound, lying in front of a home. It's not clear who the home belongs to, but Ozee didn't live there, deputies said.

Ozee was pronounced dead at the scene. The relationship between he and Contreras hasn't been confirmed, but deputies did say they don't believe the shooting was a random act of violence.

"I never thought a 16-year-old would get murdered up the street from where my nephew plays. It's really scary to think that kind of stuff happens here," said Delilah Palen, who knew the victim.

Detectives were seen collecting evidence and talking to neighbors Monday morning, trying to track down the person responsible.

Anyone with information about the shooting is asked to call the Sacramento County Sheriff's Department.