Hercules home invader tried rape in fatal attack, prosecutors say

Mark Carr Mark Carr Photo: Courtesy, Hercules Police Department Photo: Courtesy, Hercules Police Department Image 1 of / 1 Caption Close Hercules home invader tried rape in fatal attack, prosecutors say 1 / 1 Back to Gallery

Contra Costa County prosecutors charged a man with special-circumstances murder, burglary and attempted rape Friday in connection with a home-invasion robbery that left a Hercules man dead and his girlfriend — who was found with her face covered in plastic — critically injured.

Mark Carr, 27, of San Pablo could face the death penalty or life in prison without the possibility of parole if convicted in Wednesday’s attack on Buttercup Court.

Prosecutors allege three special circumstances — that the murder of Leroy Sandoval, 58, was committed in the course of a kidnapping, in the course of an attempted rape and in the course of a residential burglary.

Carr was also accused of attempted premeditated murder for injuring Sandoval’s girlfriend, Sun Arnone, authorities said.

Carr rode up to the home on a bicycle and armed with a BB gun, said Detective Connie Van Putten, a Hercules police spokeswoman. A witness later saw Carr choking Sandoval in the driveway of his home at about 2:45 p.m., prompting the witness to call police.

Carr realized he had been spotted and dragged the victim’s body into the garage before closing the door, police said.

The suspect later burst out through a back window, bending a screen in the process, authorities said.

Sandoval had clear plastic packing tape around his head and had suffered head trauma, but his cause of death hasn’t been determined. An autopsy did not find any bullets, authorities said.

Near the open front door, police found Arnone unconscious, her face covered in clear plastic, the apparent victim of asphyxiation, police said.

She was also the victim of attempted rape, authorities said. She was taken to John Muir Medical Center in Walnut Creek, where she remained in critical condition Friday.

Carr, who has two prior misdemeanor convictions in 2008 for burglary and petty theft, did not appear to have known the victims. The killing was the first in the city of 24,000 since 2012.

Henry K. Lee is a San Francisco Chronicle staff writer. E-mail: hlee@sfchronicle.com Twitter: @henryklee