The city's police officers are more likely to stop and search black and Hispanic residents than they are whites, even though whites are more often found carrying guns and contraband, according to a report released Monday by a civil liberties group.

"The results of this study raise grave concerns that African-Americans and Hispanics are over-stopped, over-frisked, over-searched, and over-arrested," wrote report author Ian Ayres, a Yale Law School economist and professor.

Ayres' report, published by the American Civil Liberties Union of Southern California, analyzed the Los Angeles Police Department's own numbers for pedestrian and motor vehicle stops in the year July 2003 to June 2004.

Even after researchers controlled for demographics and neighborhood crime rates, they found significantly higher stop rates for black and Latino residents. For every 10,000 residents, blacks were nearly three times more likely to be stopped than white and other "non-minority" residents, facing 3,400 more stops. Hispanics were stopped on 350 more occasions.

"These stark statistics ... give a numeric lens for the lived experience of 'driving while black' or 'driving while Hispanic,"' Ayres wrote.

Even though Ayres used the LAPD's own data, his findings were at odds with the department's analysis. The LAPD acknowledged racial disparities but, after controlling for a several variables, found "no consistent pattern of race effects."

A summary of Ayres' report states that over the last five years the LAPD has received nearly 1,200 citizen complaints alleging racial profiling but the department hasn't sustained a single one.

"Los Angeles officials have yet to acknowledge the scope of the problem of racially biased policing or to fully embrace solutions," the summary stated.

LAPD spokesman Officer Sam Park said the department had no immediate comment.

Not only were blacks and Hispanics more likely to be stopped than whites, they also faced increased odds of being ordered out of their car, frisked, searched and arrested. Black residents were 29 percent more likely than whites to be arrested and Hispanic residents were 32 percent more likely to be arrested, the report found.

Whites who were searched were more likely than blacks and Hispanics to be carrying guns and contraband. This shows police officers have a higher threshold for searching whites, so searches of that race are more likely to yield results, ACLU attorney Peter Bibring said.

"That result shows they are using a different standard when searching African-Americans and Latinos than they do when searching white people," Bibring said. "That kind of difference in treatment raises fundamental concerns about equal protection under the law."