POMONA — The car cruised through a dimly lit north Pomona neighborhood known as "the Islands" on a recent Sunday night. A young gang member aimed a semi-automatic military assault rifle through an open window and pulled the trigger.

By the time the shooting stopped, five people had been injured and a sixth, 19-year-old Guadalupe Carrillo Garcia, was dead from a bullet wound to the stomach. Police don't believe that any of the victims were gang members. They were just unlucky enough to be on the streets when a gang from elsewhere in the city came to settle a score.

The night before, Charles Bradford Thomas, 30, a suspected gang member, was killed in a drive-by shooting as he stood on the street in a northwest Pomona neighborhood known as "Sintown." Police said the shooting was apparently the result of a dispute between two rival gangs over drug-dealing territory.

A 17-year-old suspected gang member, whose name was not released because of his age, was arrested on suspicion of murder in connection with the retaliatory shooting spree. Police said they have not identified any suspects in the shooting that triggered the violence.

Bloods or Crips

Police refused to name the gangs involved because they did not want to glorify their exploits. However, they said most black gangs are affiliated with either the Bloods or Crips, two Los Angeles-based gangs marked by their display of the colors red or blue, their involvement in the drug trade, and their violent antipathy for each other.

According to residents of northern Pomona, the Islands belong to a gang affiliated with the Bloods, while Sintown is Crips territory. And either neighborhood can be the site of bloodshed at anytime.

Both areas have been relatively peaceful since the shooting spree on Jan. 22, but police and residents are bracing for the next round of confrontations and pay-backs.

"It's been quiet since then," said Sgt. Gary Elofson, who heads the Pomona Police Department's Crimes Against Persons Unit. "We don't expect it to stay that way."

Last month's shootings started the year off ominously in Pomona, which had only two homicides involving black street gangs last year. Police are reluctant to describe the incidents as symptomatic of increased activity by gangs affiliated with Bloods and Crips, but others who monitor youth crime in the city are not.