Robbers Kill Man Walking on Manhattan Beach : Violence: Crime shocks the community. In North Hollywood, a teen-ager driving to a birthday party is shot to death by an alleged gang member.

A 25-year-old man strolling the Manhattan Beach shoreline with his girlfriend was stabbed to death early Sunday after the couple tried to run away from robbers, authorities said.

The rare surfside attack occurred as the West Los Angeles man and his 22-year-old companion from Huntington Beach sought to flee after being stopped and robbed at knifepoint by three men about 2:30 a.m.

The victims apparently did not know their attackers, said Manhattan Beach Police Sgt. David Ferguson, who called it “a crime of opportunity.” They are still at large.

In North Hollywood, a 17-year-old boy who “wanted to be an accountant” was shot and killed Saturday night by an alleged gang member who fired at him and his friends from a Range Rover, police said.

Andrew Villanueva, 17, was “an innocent victim” who unwittingly drove into gang territory on his way to a friend’s quinceanera, a traditional 15th birthday party for Latinas, said Lt. Ron LaRue, who added that two arrests have been made in the killing.

In the Manhattan Beach attack, police did not immediately identify the dead man, who died at the scene from multiple stab wounds. The woman, who was not identified by police, was stabbed once in the stomach and was hospitalized in stable condition, authorities said.

The homicide shocked Sunday beach-goers in the normally tranquil South Bay city, where the ronly other homicide in nearly a decade was the shooting death of Manhattan Beach Police Officer Martin Ganz as he made a traffic stop in December, 1993.

On balmy evenings, late-night strollers are a common sight, both on the sand and on The Strand, an oceanfront pathway that runs next to million-dollar homes.

“You’d never expect it in this community,” said Manhattan Beach resident Scott Bowen, 25, a former lifeguard. “It’s a real family type community, and you get the feeling that people from the outside are coming in.”

“I come here to get away from that stuff,” said Michael Reed, 24, of West Los Angeles, who was basking in the warm afternoon sun. “Manhattan Beach is one of the last places I think that can happen.”

Ferguson said the couple, strolling near the surf about three blocks south of the Manhattan Beach Pier, were accosted by three men who demanded their money and jewelry. After complying, the victims, apparently fearing for their lives, tried to flee, police said.

The attackers tackled the man and stabbed him repeatedly, police said. They stabbed the woman at least once, but she was able to leave the scene and reach the pier, where a police car was patrolling.

When officers returned with her to the scene, the victim was dead, police said. The attackers were last seen driving north on Manhattan Avenue in what witnesses described as a medium-sized, white or light gray beat-up car.

At sunrise Sunday, as surfers hit the waves, police had cordoned off a section of sand to search for objects such as jewelry that might serve as clues in the crime.

“This comes as quite a shock,” said one wet-suited surfer, Mitchell Mosse, 38, of Lennox, later in the day. “This is one of the best beaches I’ve ever been to.”

In the North Hollywood killing, police said Villanueva and a friend were heading to the party in his Buick and four others were following in a second car when alleged gang members began shouting at them and fired once.

The two cars fled, but when the drivers stopped to discuss the incident, the Range Rover pulled alongside and a man identified as Ernest Martinez Luera allegedly shot five to seven times, hitting Villanueva, Detective Mike Coffey said.

Police found the Range Rover parked a few blocks away and arrested the suspected driver, Debra Ann Rakdahl, 30, on suspicion of murder. Police later arrested Luera, 22, of Burbank.

“He wanted to be an accountant,” said the dead youth’s father, Placido Villanueva. “He never used drugs, no drinking, no smoking, anything.”