SANTA MARIA (AP) — When a police officer dies on the job, a department and a community mourn together. But not this week in Santa Maria, where they are too stunned and outraged.

Officer Alberto Covarrubias Jr. was shot and killed early Saturday at the end of his shift working a DUI checkpoint. The shooter was his best friend on the force and best man at his wedding just three weeks earlier.

More shocking still was that the shooting occurred as detectives moved in to arrest Covarrubias, 29, on charges of having sex with a 17-year-old girl.

Now, as Covarrubias' family prepares to bury him without a police funeral, two retired officers who spoke to police at the scene of the shooting offered new details of the case:

— The girl was a member of the department's Police Explorer program for young people interested in law enforcement careers.

— A lieutenant at the checkpoint had alerted the officers assembled, including Covarrubias, that the girl was part of an investigation and that she was going to be pulled off checkpoint duty.

The former officers disclosed the details to The Associated Press only on condition of anonymity. Police officials have not returned repeated calls seeking comment.

Since the shooting, a memorial of candles and flowers has risen where Covarrubias was killed. The death of an officer on duty is rare, though the city came close in December when two were wounded by "friendly fire" during a botched SWAT team raid.

"It doesn't make sense," said Davinder Singh, who manages the 7-11 store 50 yards from the memorial. "It's not supposed to happen that way."

Santa Maria, nestled between oak-studded hills and cooled by the Pacific 10 miles away, is a mixture of 1950s California and the kind of stucco-clad, cookie-cutter development seen elsewhere. Over the years, Latinos have increasingly moved in to the city about 170 miles northwest of Los Angeles.

It's easy to see their influence — they now comprise 70 percent of the city's 100,000 residents. A new Rite-Aid drug store sits around the corner from a Mexican herbal medicine shop, Clinica Naturista. And a throw-back hamburger stand on the main drag serves menudo, a Mexican stew, on weekends.

Killings are uncommon; the city averages less than a half-dozen homicides a year, mostly gang-related. But the recent spate of violence has some city officials worried.

"We're in tough times trying to get business and people to settle here," said Mike Cordero, a City Council member who served 30 years on the Santa Maria police force.

Police have disclosed few details about the Covarrubias case, leaving residents to wonder why police felt compelled to make the arrest while the four-year veteran was on duty and how it could have ended with a bullet in the officer's chest.

Covarrubias' family wants answers, too.

"What happened to procedure?" asked his father, Alberto Covarrubias Sr. "Why did they go to arrest him in the field? If it was so urgent why didn't they just say there was a family emergency and he had to come to the station?"

Chief Danny R. Macagni did not respond to repeated requests for an interview, nor did City Manager Rick Hayden or City Attorney Gilbert Trujillo.

At a news conference the day after the shooting, neither Macagni nor his top deputies were wearing the black bands across their badges that are customary after an officer is killed.

"Events unfolded very rapidly," he said. "It was very clear to the investigators that he knew what was going to happen. I cannot divulge why we know that. The information that we had we knew we could not let him get in the car and drive somewhere.

"But we did not expect him to react the way he did," he added.

Covarrubias, a 2000 graduate of Santa Maria High School, always wanted to be a cop. His classmates said he was a funny and charming guy. He had recently remarried — a woman with whom his father said "he just clicked" — 13 months after his first wife committed suicide during their divorce proceedings.

He once was heralded as employee of the month in the department of 105 for nabbing an ATM robber, his father said. Last fall, he was named to the motorcycle unit. "My son was proud to be a cop," he said. "He was a good cop. Now they're dragging his name through the mud."

Everyone has the same question: Why did police try to arrest Covarrubias while he was armed with his service pistol and aware of the investigation?

"I'm concerned about what's happening and it goes beyond the shooting of an officer. It reflects on the management of the police department," said Toru Miyoshi, who formerly served on both the city council and the Santa Barbara County Board of Supervisors.

"They could have waited for a more controlled situation. A DUI checkpoint does not just put the accused at risk but it puts the public at risk as well," Miyoshi said.

It's unclear for how long Covarrubias and the girl carried on a sexual relationship, but she confided to an adult described as a "mother figure" on Thursday — Covarrubias' birthday — that the two "were dating." The woman called police, the retired officers said.

Police decided to set up a sting to arrest Covarrubias on sexual misconduct charges. In California, the age of consent is 18 unless the two people are within three years of each other in age.

Before the DUI checkpoint started, the lieutenant in charge was told that the Explorer Scout was going to be called away to do a "pretext call," the name for setup calls designed to get suspects to confess with investigators listening in, both retired officers said.

For reasons unknown, the commanding officer told all of the officers at the checkpoint, including Covarrubias, that the girl would be called away for an investigation, they said.

The officers, who have more than six decades of experience between them, independently described what happened that night.

Covarrubias panicked when he heard the commanding officer's announcement about the pretext call, the officers said. He texted the girl, asking if she had spoken to investigators.

Investigators proceeded with their plan, sending the "mother figure" to fetch the girl and tell her there was a family emergency. Covarrubias saw the girl leave and became frantic.

"As soon as she gets pulled out he starts texting her again," said one of the retired officers. "He started texting stuff like 'I'm not going to jail' and 'I'd rather kill myself' and that type of stuff."

Soon the girl called Covarrubias' cell phone and, though he knew she was part of an investigation, he acknowledged their sexual relationship, the former officers said. After hanging up he sent a text saying that he hoped the call wasn't set up by the department.

Sometime around 1 a.m., two sergeants — one of them the officer's cousin — arrived to take Covarrubias into custody.

Covarrubias backed up and, according to police, tried to draw his gun as the sergeants wrestled him to the ground. Police at the scene told the retired officers that Covarrubias fired four times, but not at anything or anyone.

Then, he pointed his pistol at his best man, Officer Matt Kline, the retired officers said. Kline fired his weapon, fatally wounding his friend.

The department denied Covarrubias a police funeral, said his father, who then opted not to bury his son in the uniform he loved.

"What happened to the brotherhood?" the father asked. "This is all stewing inside of me. I should have my son here, not be planning his funeral."

___