A Hesperia man pleaded not guilty Thursday to a charge of first-degree murder in connection with the August shooting death of his alleged lover's husband in Tehachapi.

Jonathan Michael Hearn, 24, wore paper clothing in his first court appearance, an indication he is on suicide watch. The District Attorney's office has not yet decided whether it will seek the death penalty in his case.

The murder charge has been filed with enhancements of lying in wait and using a firearm.

Hearn and Sabrina Limon were arrested Tuesday on suspicion of murder and conspiracy in the death of Limon's husband, Robert Limon. Sabrina Limon, 35, was not charged as of Thursday afternoon because of insufficient evidence, prosecutor Esther Schlaerth said.

Schlaerth declined to provide further details on the case.

The Kern County Sheriff's Office website showed Sabrina Limon was still in custody as of 4:45 p.m.

Robert Limon, of Helendale in San Bernardino County, was found dead of gunshot wounds Aug. 17 in a Burlington Northern Santa Fe Railway industrial complex at 1528 Goodrick Drive in Tehachapi. The 38-year-old had been last seen by coworkers after leaving fieldwork about 5 p.m.

Kern County sheriff's detectives have said they looked into hundreds of leads and developed information Sabrina Limon and Hearn were in a relationship before the shooting.

Hearn's attorney, Clayton Campbell, said after his client's arraignment there was a substantial amount of evidence to study.

"This is the United States of America," Campbell said. "Just because you're accused it doesn't mean you're guilty."

Hearn is next scheduled to appear in court Dec. 5. He's being held without bail.