2 Men Arrested in Pair of Park Rape-Robberies : Crime: A neighborhood surveillance team helps police stake out the Chatsworth site where attacks occurred July 1 and 6.

With the help of a neighborhood civilian surveillance team, police have arrested two men suspected of raping two women and robbing their male companions in a remote west San Fernando Valley park that has been the scene of at least one similar attack in the past.

In custody Wednesday were Francisco Javier Ochoa and Jose Abran Umanzor, both 21-year-old natives of El Salvador who lived in Canoga Park and worked in a local carwash. The two men were arrested Saturday night by a task force of detectives staking out Chatsworth Park North with the help of several members of a local crime-fighting group known as the Devonshire Area Volunteer Surveillance Team, Los Angeles Police Lt. Kyle Jackson said.

Although the victims and male friends who were accompanying them never got a close look at their assailants, Ochoa and Umanzor were arrested after spending more than an hour loitering and “acting suspiciously” in the park, said Detective Sandra Palmer, coordinator of the LAPD’s Devonshire Division Major Assault Crimes section.

“We think we have an extremely strong case against these individuals,” Capt. Vance Proctor, commanding officer of Devonshire Division, said at a news conference police held at the park Wednesday to announce the arrests.

Charges of rape, sodomy and robbery were filed against the men late Tuesday, and they were being held Wednesday on $500,000 bail each.

The attacks came almost exactly one year after another series of late-night armed robberies and rapes in West Valley parks prompted police to warn residents to avoid some of their local recreation areas.

In the current cases, police put more than a dozen undercover officers in Chatsworth Park North on the night after the second rape July 6, some of them posing as couples.

Police arrested the two men as civilian volunteers stood lookout with police radios, and recovered a plastic gun and two knives believed to have been used in the attacks, according to Palmer and other detectives.

“The secret is we have citizens who really care about their community, and officers who really want to work with us,” said volunteer Michele Doubet, who said she and about 40 other volunteers have helped police arrest dozens of suspects on a variety of charges in the past two years. “We have formed a very successful partnership.”

Because of striking similarities to cases last summer, authorities at first were suspicious that the attacks were the work of members of the same organized gang, but later discounted that theory.

In the first attack, at 9 p.m. on July 1, two men snuck up on a 22-year-old female and her 23-year-old male companion while they were sitting on swings in the park’s playground area, according to police. The female victim was dragged into some bushes at gunpoint by one of the suspects and sexually assaulted while the other suspect tied up the male victim and robbed him at knifepoint, police said. The suspects then switched places and the second man sexually assaulted the woman.

On July 6, a second, nearly identical attack occurred nearby just before 10 p.m. Police said the same two suspects were responsible, based on circumstantial evidence. By the next night, officers were out in force in the park and arrested the two suspects the night of July 9 after they allegedly approached another couple, who fled and alerted plainclothes officers to watch out for men hiding in the bushes, Palmer said.

The two suspects were arrested an hour later when police blinded them with high-powered flashlights and grabbed their weapons. Although the gun they recovered was plastic, authorities said it was the same one used to scare the victims in the two earlier cases. “The victims believed that the gun was real,” said Detective Debra Kirk, one of the undercover officers who arrested the suspects.

Last year, West Valley residents were warned to stay away from parks after several women were raped, some while male companions were tied up and robbed nearby. Four transients were arrested and pleaded guilty to various charges three months ago, leading to a 45-year prison sentence for the alleged ringleader.

At least one robbery occurred in Chatsworth Park North, when two women were robbed by two men but fended off sexual assaults by screaming.

“The (cases) are remarkably similar, but we haven’t established a relation between the cases or the suspects . . . “ Palmer said.

“It’s not like they are in the same gang or anything. We don’t have anything to indicate they are even in a gang. But it got our attention right away. Because of last year, we recognized that we could have a problem.”