5 in Family Found Shot to Death in Home : Crime: Boy, 3, is only survivor of what San Bernardino police speculate was a robbery. In Riverside, three unrelated females are slain in apartment. A baby is spared.

SAN BERNARDINO — Five members of a Vietnamese family were found shot to death Thursday in a suburban neighborhood so dulled to the sound of gunfire that neighbors did not report the shots.

The only survivor was a 3-year-old boy who apparently spent the night alone with his dead parents, two sisters and a brother, and related the death scene to his aunt who happened to call the home the next morning.

The aunt then called a neighbor to check on the boy’s safety and the carnage was discovered, said Jim Hamlin, a spokesmen for the San Bernardino Police Department.

The neighbor, Vanessa Evans, told reporters that three victims appeared to have been shot in the back. Their bodies were found in a front room of the house. A younger victim was discovered dead in his bed.

The names of the victims had not yet been released, but a relative of the victims said the children were about 11, 12 and 13 years old. The 3-year-old boy was hospitalized in good condition with a gunshot wound to his arm, Hamlin said.

There were no known suspects or motive in the shooting, but Hamlin speculated that the family might have been victims of a home-invasion robbery.

Three years ago, members of an Asian gang held a family hostage for two days in another home several blocks away before surrendering, Hamlin said.

Neighbors acknowledged Thursday that they heard a quick burst of gunfire coming from the home in the 1600 block of Elm Street where the killings occurred, but stayed inside and did not call police.

“It was real quiet [Wednesday night] and we were in bed watching TV,” said Alfonso Lopez, whose house backs up to the victims’ home. “Then at 10:35 I heard bam-bam-bam-bam-bam, six to eight times right in a row like an automatic pistol was going off. It sounded like it came from one gun. . . . I feel real sorry that I didn’t call 911.”

Cathy Aceres, who lives with Lopez, said she heard the same staccato gunshots breaking the quiet of the neighborhood. “There was no screaming, no crying, just the shots. We were so scared we didn’t go outside.”

Other neighbors said they have grown accustomed to the sound of gunfire in the rough-hewn neighborhood of single-family homes.

The killings were the second multiple homicide to confound authorities in the Inland Empire on Thursday.

In nearby Riverside, firefighters responding to a report of smoke about 8 a.m. Thursday discovered the bodies of three slain females in an apartment complex, and rescued a 7-month-old boy before he was overcome by smoke.

Riverside Police Sgt. Bob Hanson said the unidentified victims, whose ages were 12, 15 and 19, were unrelated to one another and suffered a “highly traumatized, brutal death.” He would not say how the three were killed but called it “a very violent crime scene.”

Hanson said the smoke that led to the discovery of the bodies apparently came from something flammable--maybe a pillow--being placed atop a stove burner in the two-bedroom apartment, perhaps to cover up the killings by fire.

The oldest victim was the apartment tenant and mother of the infant, and the other two females were visitors there, Hanson said. There was no known motive for the killings and no suspects, he said.