Mother Says Boy, 10, Admitted Fatal Shot : Crime: Emerging picture shows a child who was undisciplined and headed for trouble.

SAN DIEGO â€”  The 10-year-old boy arrested in connection with the shooting death of a 25-year-old woman told his mother he believed he fired the fatal shot, but said he was only trying to shoot a light out inside the woman’s trailer.

In an interview Thursday, the boy’s mother, Marta, said she will ask authorities to keep her son locked up somewhere, hoping that discipline and a structured environment will help him turn his life around.

“He needs to be in a place where someone can have some control over him. You know, he’s only 10,� said Marta, who is raising six other children on her own.

District attorney’s office spokesman Steve Casey said the youth was being held at Juvenile Hall pending further proceedings. He was arrested on suspicion of shooting a firearm within city limits and shooting into an inhabited building.

Police said they have not yet decided whether to pursue homicide charges in the death of Manuela Garcia de la Rosa, shot as she got one of her three children ready for bed. Her husband, Fidel Mariscal, said he believed the youth may have been angry with him because he had refused to lend him his motor scooter.

On Sunday night, police said, the boy and two male companions, ages 13 and 14, were shooting a .22-caliber Uzi-type weapon from a roof across from the trailer. Investigators said the older boys shot the gun into the air.

After visiting her son at Juvenile Hall on Thursday, Marta, whose last name is being withheld to protect the family’s identity, said the boy was frightened and tearful as he admitted firing the shot that killed De la Rosa.

“When he fired, he didn’t know if he hit anybody,� she said. “They weren’t trying to shoot at anyone. He said all three of them were trying to hit a light inside the trailer.�

However, police said that the bullet fired by Marta’s son was the only one that hit the trailer.

Homicide Lt. John Welter said Thursday that investigators have not recovered the weapon used to kill De la Rosa and do not know how the youths acquired it.

“We don’t know where it came from, but it’s our opinion that it was picked up from the streets by one of the three juveniles,� Welter said.

Both Marta and the mother of her son’s alleged 14-year-old accomplice said they gave police their consent to administer polygraph tests to their sons.

Interviews Thursday with the 10-year-old’s mother, neighbors and counselors revealed a picture of the boy as stubborn, undisciplined and headed for trouble.

Two years ago, he watched as his older brother was killed in a drive-by shooting in another tough Latino barrio, according to counselors at the Barrio Station, a community service group.

His single, unemployed mother is raising him, four sisters and two brothers on public assistance checks. Last Christmas, volunteers painted the youth’s ramshackle home, got the family a color television set and bought shoes for each of the children.

The boy was kicked out of two elementary schools for fighting and mouthing off to teachers, and often roamed the streets of his neighborhood, imitating the cocky swagger of hard-core gang members.

San Diego police officers occasionally picked up the youth at Chicano Park--a high crime area located in the heart of Barrio Logan--at 2 a.m. and drove him home.

The youth was already an accomplished tagger--a painter of gang graffiti. His spray-painted tagline, “Loops,� was a common sight in the neighborhood.

Barrio Station Executive Director Rachel Ortiz said Thursday that she and her counselors warned Marta and her son about the path of crime the boy was following. Ortiz, an ex-con and former heroin addict, knew what she was talking about.

“He was really impressed by prison and the ex-cons in the neighborhood. He glorified prison,� Ortiz said.

Ortiz, who counseled the boy almost every afternoon when he came to use the recreation facilities, described him as “hard and aggressive.�