olice chiefs across Massachusetts were smarting yesterday at a state official's ruling that 249 police departments showed evidence of engaging in racial profiling.

"An awful lot of my colleagues feel that we've been thrown under the bus," said Police Chief Edward M. Merrick Jr. of Plainville, former president of the Massachusetts Chiefs of Police Association.

"You've got 249 communities who have been stigmatized today," said Merrick, whose community was on the short list of those not censured.

The state secretary of public safety, Edward A. Flynn, announced that 249 police departments have shown racial disparities in traffic enforcement and therefore must collect more information on every traffic stop, even those that don't result in a ticket or written warning.

Flynn based his decision on a state-sponsored study by Northeastern University, which found that three-fourths of the 341 police departments studied had significant disparities in either ticketing or searching of minority motorists. The agencies on the list include the State Police, the Boston Police Department, and all of the state's larger cities and towns.

"We are not today finding any agency guilty of racial profiling," Flynn said at a meeting of police chiefs and community leaders at Northeastern. "What we have is a disparity."

Flynn said that the disparities could result from good police work, perhaps, he suggested, in minority communities that have asked for more traffic enforcement or in high-crime areas. The disparities could also result from bias, the result of individual officers being more likely to give whites a break. But Flynn said he chose to "cast a wide net and require communities with any disparity to collect data."

"Every community deserves an explanation for the disparity," said Flynn, who was the police chief in Braintree and in Chelsea. "Every police chief owes that explanation. . . . Nothing is more important than trust in police officers and in their use of their discretion."

To soften the blow, Flynn said he will spend $1 million on several changes, including software to help police chiefs get regular management reports on the race and gender patterns of traffic stops by each officer. Part of the money will be used for grants to help police departments and community groups begin a dialogue on racial profiling and police-community relations.

Flynn's decision was welcomed by minority leaders, who said it reinforces their everyday encounters with police.

"What has been the real experience of people now has some statistical weight behind it," said the Rev. Jeffrey Brown of Union Baptist Church and the Boston Ten Point Coalition.

"My goal is that eventually we will have a generation of young people who will not feel that police are against them," he said. "We have community residents who want more law enforcement, but who are afraid to ask for it, because they perceive that law enforcement is set against them."

The American Civil Liberties Union called for the Legislature to put teeth into the profiling law, with penalties for communities that show disparity. The ACLU and several civil rights groups have scheduled a news conference at 9 a.m. today at the State House.

The new traffic forms must be filled out for a year, starting as soon as the forms are designed. They will record such information as the reason for the stop, the reason for any search, what was found in a search, the location and time, the driver's race and sex, and the officer's name and ID number.

Such information has been collected in other states, Flynn said, but is being required under Massachusetts law only in those communities that showed disparities on the study of traffic tickets and warnings. Police departments can appeal Flynn's decision to Attorney General Thomas F. Reilly.

Researchers from Northeastern University's Institute on Race and Justice studied 1.6 million traffic citations issued between April 1, 2001, and June 30, 2003. The results confirm a study by the Boston Globe last year, showing that minority members, especially men, are disproportionately ticketed -- even when they are stopped for driving the same speed as women and whites who get a warning -- and are searched for contraband more often, even though searches of white drivers were more likely to find drugs.

A Boston police union official said the study was driven by a political agenda and officers will respond by doing fewer traffic stops.

"Police officers, already second-guessed and harangued by the media, will respond by not enforcing traffic laws, out of a legitimate and real fear of being forced to participate in the manufacture of their own noose," said James W. Carnell, a patrolman and area representative for the Boston Police Patrolmen's Association.

The lawyer for the police chiefs association, John M. Collins, called Northeastern's report "voodoo math," disputing estimates of how many minority drivers are on the road in certain communities.

Instead of paying for more data collection, the chiefs said, the state should pay for more training for all police officers, and discipline for any who commit acts of bias, as well as for a public relations campaign to encourage citizens to look for unlawful behavior before calling police.

"Police officers in Massachusetts do a remarkable job at protecting our citizens, addressing crime, and enforcing the law in an even-handed manner," said Richard A. Marchese, the former police chief in Longmeadow and executive director of the Massachusetts Chiefs of Police Association.