Officer Slain in Apparent Robbery : Crime: He is killed by a fellow deputy, who was also a friend, from the Encinitas station. The dead man was off duty and wearing a mask. Accomplice escapes.

An off-duty sheriff’s deputy was shot and killed Wednesday by a fellow deputy, and close friend, who found him beating the owner of an Encinitas-area home during an armed robbery, authorities said.

San Diego County Sheriff’s officials said Deputy Michael Stanewich, 36, an undercover narcotics detective and nine-year veteran, was fatally wounded by Deputy Gary Steadman, 35, an 11-year-veteran who had responded to a report of a residential armed robbery and confronted Stanewich, who was wearing a stocking mask.

Both officers worked out of the same Encinitas sheriff’s station, but the uniformed deputy did not recognize his friend until he removed the mask from the dead man’s head.

Stanewich had been to the home in the unincorporated Olivenhain area owned by Donald Van Ort last week to search for narcotics and noticed a large amount of cash that was not seized, investigators said. On Wednesday, they said, the deputy returned with an unidentified accomplice to steal the money, estimated to be about $100,000.

The accomplice fled after Stanewich forced his way into the house at gunpoint and confronted Van Ort, 32, and his 82-year-old grandmother, Helen Van Ort.

Van Ort’s girlfriend, Carla Jo Sawcliffe, escaped and telephoned authorities.

Meanwhile, the robber tied and gagged the elderly woman and threw her onto a couch. He handcuffed Van Ort to a chair, placed a pillowcase over his head, beat him, poured lighter fluid on him and threatened to set him on fire, authorities said.

Steadman and Deputy Christopher Matchitar arrived at Van Ort’s home in the 200 block of Cole Ranch Road at about 10:40 a.m.

Authorities said Steadman opened the front door and saw the masked intruder in the kitchen beating and threatening to kill Van Ort, who by that time was hogtied on the floor.

According to investigators, Steadman identified himself as a deputy and told the robber to freeze, but the man flailed his arms near a knife that was lying on a sink. Steadman ordered the masked man to freeze again, but he moved toward the deputy.

Steadman fired three rounds, striking Stanewich twice in the upper body. Then he reached down and pulled the mask away as Stanewich lay dying.

Sheriff Jim Roache described the two deputies as close friends, who often worked and socialized together.

Van Ort, bloodied and bruised from the beating, told authorities that he recognized Stanewich as the person who searched his home the week before. Van Ort, arrested twice in 1989 for drug-related infractions, violated probation and was assigned to a residential drug treatment center last November, according to court records.

Officials described Stanewich’s accomplice only as “slightly built, dark complexioned male.” They said they have no reason to believe he is a deputy.

News of the shooting rocked the Sheriff’s Department.

“Our entire department is repulsed by this double tragedy,” Roache said during a news conference. “A deputy, one of our own, was apparently committing a terrible felony. Another deputy, who knew the perpetrator through law enforcement activities, doing his duty properly was forced to kill the apparent criminal.

“It is an understatement to say we are both angered and saddened.”

Stanewich leaves his wife, Kathy, and three children, ages 4, 3 and 22 months.

In 1989, Stanewich was selected, along with four other deputies, by the Encinitas City Council for “outstanding service to the community.” In 1987, he shot and injured a man in Solana Beach who was charging at him with a gun.

Because of the circumstances surrounding the shooting, no flags will be flown at half-mast, no black tape affixed to badges and no uniformed deputies will appear at Stanewich’s funeral, Roache said. Steadman was undergoing counseling, department officials said, and will be placed on administrative assignment while the investigation proceeds.

“It’s been a tumultuous, heart-wrenching, gut-wrenching day,” Roache said late Wednesday. “I’m numb and the people in this department are numb. It’s going to take a long time for people to absorb and deal with this.”

Times staff writers Barry M. Horstman, John M. Glionna, Michael Granberry and Jonathan Gaw contributed to this story.