Boy, 10, Arrested in Shooting That Killed Mother of Three : Violence: A bullet pierced the wall of trailer and hit her as she put her son to bed. The victim’s husband believes the action may have been intentional.

A 10-year-old boy was arrested Wednesday in connection with the death of a young mother of three who was killed as a bullet pierced the wall of the trailer where she lived, striking her in the back of the head as she put her son to bed.

The husband of the dead woman said Wednesday evening that he thinks the shooting might have stemmed from his refusal to lend his motor scooter to the boy and his friends.

“I can’t explain it . . . but I don’t think it was an accident,” Fidel Mariscal said. “Possibly they were trying to scare me . . . possibly they were trying to hurt me. I think it was intentional.”

Manuela Garcia de la Rosa, 25, was killed Sunday night as she put her 8-year-old son to bed.

The juvenile suspect was arrested on suspicion of shooting a firearm in city limits and shooting at an inhabited building. Police are looking into the possibility of homicide charges. In addition, police detained but did not arrest two other boys, 13 and 14. Police said the youths took turns firing a .22-caliber rifle from a neighbor’s rooftop, but the youngest boy is believed to have fired the shot that killed Garcia.

Detectives said they still are trying to determine if the shot was directed at the trailer or was fired randomly.

“It’s possible this was an indiscriminate shooting,” said San Diego Police Lt. John Welter. “If it was, it’s not only sad--it’s sick.”

Police said they found the boys by using a laser beam to trace the trajectory of the bullet from the hole in the trailer wall. The beam led to the roof of a one-story house in the alley behind Garcia’s trailer. By questioning neighbors about who had access to the rooftop, Welter said, police were able to locate one of the boys.

All three youths live within two blocks of Garcia’s trailer, Welter said. The 14-year-old had been under house arrest for a prior conviction, the lieutenant said, but no details were released. Police are looking for a fourth youth who might have the gun.

Although police said it was not clear whether the youths knew Garcia or her family, Mariscal, 32, said he had been involved in several minor run-ins with the boys.

Mariscal said the 10-year-old had once borrowed his Yamaha motor scooter and might have been angry because Mariscal balked at lending it again.

Demands to borrow the scooter began a few days after Mariscal moved to the neighborhood last month and were repeated during the five weeks leading to the shooting. On one occasion, the youngest boy tried to ride off on the scooter when Mariscal was at work, he said.

“I think my mother or my wife, I’m not sure which, told him not to do that,” Mariscal said. “But they didn’t touch him. They didn’t offend him. We didn’t offend him in any way.”

Garcia’s death was only the latest sign to residents of Barrio Logan that the crime-ridden San Diego neighborhood is deteriorating.

“People are shooting up the barrio so often now, its surprising there haven’t been more innocent victims,” said a neighbor, Al Ducheny, who is chairman of the Harborview Community Council, an area advocacy group. “There is no longer a fear of retribution for crimes committed in our community. Anything goes in Barrio Logan.”

As newcomers to the barrio, Garcia and Mariscal always worried about the sounds of gunfire ringing through the neighborhood.

They looked for a house that would accommodate their two sons and daughter, and the families of two of Mariscal’s siblings. The 14-member extended family chose a ramshackle, two-bedroom house across from a metal plating shop and up the block from a shipyard. They heard the area had problems with crime, but it was cheap.

Mariscal’s parents stayed in the house. The three other families lived in separate trailers in a cramped back yard.

In forming their small family compound, they thought they could insulate themselves from the dangers of the street, Mariscal said.

“As long they didn’t mix with the neighborhood, they thought they were going to be OK,” said Mariscal’s aunt, Teresa Avalos.

But at 9 p.m. Sunday, the streets came calling.

A bullet crashed through the west wall of Garcia’s trailer. One moment, she was undoing the laces on Fidel Jr.’s high-top sneakers. The next, she lay on the floor, her head surrounded by a growing pool of blood.