(CBS) OAKLAND, Calif. - Oakland's police chief says the wave of shootings that left four dead and 11 wounded since Friday may be the result of a feud sparked by the murder of a woman last summer, reports CBS San Francisco.
At a news conference Monday, Oakland Police Chief Howard Jordan said that two groups apparently at war with each other are responsible for "90 percent" of the violence in the city since then.
Police said one suspect in the weekend shootings is in custody.
There were four separate murders within six hours Friday afternoon and evening, with three men and a 17-year-old killed in what police believe were related, retaliatory shootings.
Three people were wounded Saturday afternoon in a shooting on Harmon Street. There was another shooting later that night, followed by two more on Sunday.
According to police, they don't know if the later crimes were related to incidents on Friday. They've been trying to get a grip on the homicide rate and plan to hire former New York and L.A. police chief Bill Bratton as a consultant, but Jordan said there's no need to formally declare an emergency or to seek more outside help.
"We know who the bad guys are and we're focused on getting them," Jordan said, blaming a narrow segment of the population for the uptick in violence. Jordan said the murder of a young man's girlfriend last year has set off a series of attacks and retaliatory shootings that have had a direct impact on the city's crime statistics.
Mayor Jean Quan said the problem is exacerbated by the firepower the rival sides are packing.
"These kinds of fights between gangs didn't used to end with a dozen murders. Because of the availability of guns, we've got disputes by very young people and shooters who are very young, who have access to guns that are totally out of control," said Quan.
Police seized 11 assault weapons and high-capacity magazines and have a warrant for a second murder suspect in connection to at least one of these incidents.