FARMINGTON — The suspect in Monday night's fatal shooting of a Farmington woman was previously arrested for stalking and threatening to kill a local teenager, according to court documents.

Jacob Beach, 19, was arrested Tuesday night and charged with an open count of murder. Police said he shot and killed Sharolyn Keown, 18, outside a home at Mockingbird Trailer Park, where she was living with her boyfriend.

Beach is being held at San Juan County Adult Detention Center on a $500,000 cash-only bond and is scheduled to appear in front of a magistrate judge at 10 a.m. Thursday.

Beach was arrested at Enchantment Motel in Aztec and booked into jail at 10 p.m. Tuesday. He has declined to speak with police since his arrest, Farmington police Sgt. Robert Perez said.

In May 2011, Beach was arrested for stalking and harassing a 16-year-old Farmington girl. In July 2011, he pleaded guilty to harassment and was sentenced to one year of probation, according to court documents.

Beach and the girl, whose name is being withheld, were in a relationship for about two years. After the couple split, Beach started texting her, leaving notes on her car and followed her, according to court documents.

Beach threatened the girl in many of the text messages and she filed a restraining order against him.

"Don't forget I know where you sleep," he texted her, according to court documents.

In March, Beach was arrested for possession and distribution of marijuana but the charges were dismissed, according to a state court website.

Beach was a former Piedra Vista High School student. Keown was a former Farmington High School student.

Farmington schools Assistant Superintendent Frank Stimac said neither Beach nor Keown had been students at the schools in more than a year.

Beach reportedly lived near San Juan Country Club.

Monday's fatal shooting was reported to police at about 11 p.m.

Keown was upset with Beach because he had attempted to sexually assault her several months ago witnesses told police. According to the police report, she confronted Beach in an undeveloped field near the mobile home complex and was shot.

Keown was shot in the chest near her collar bone and died at the scene, according to court documents.

Police found a handgun at the scene but don't believe it was the one used in the shooting, Farmington police Sgt. Robert Perez said.

"We do believe there was more than one firearm on scene and we are still in the process of determining what firearm was used to commit the crime," he said.

Perez said the hand gun used in the homicide may have been taken part and scattered. Anyone who locates possible parts is asked to call 505-599-1005.