New Haven - The police department in suburban East Haven engaged in a pattern of discrimination against Latino residents, according to investigators from the U.S. Justice Department, who said Monday that their probe was complicated by efforts to interfere with witnesses and a "blue wall of silence."

The investigation by Justice's civil rights division examined traffic stops from 2009 and 2010 and found "a pattern or practice of biased policing" and a "failure to remedy a history of discrimination and a deliberate indifference to the rights of minorities."

Nearly half or a third of the drivers pulled over by certain officers were Latino, and the number of Latinos pulled over by certain squads was "extraordinarily high," said Roy Austin Jr., deputy assistant attorney general for the civil rights division. Latinos who were stopped for minor violations were subjected to harsher punishments, such as arrest or vehicle towing, than were non-Latinos.

"No matter how we looked at it, we found problems," Austin said.

In at least one case, the report mentions how an officer looked up the insurance information for a moving vehicle to find a reason to stop the car.

The coastal community was 88.5 percent white and 10.3 percent Hispanic or Latino in 2010, compared with 4.4 percent Hispanic or Latino in 2000, according to census figures.

Jim Krebs, a member of the commission that oversees East Haven police matters, said he had no personal knowledge of the problems but respected the work of the federal investigators and said their work was thorough.

"I think you're going to see a much improved department for East Haven and the citizens of East Haven. We hopefully will be a model police department in the state of Connecticut," Krebs said, calling the revelations an embarrassment.

The Justice Department will reach out to the police department, town officials and the community to work on reforms, Austin said. If the police department or town officials do not cooperate, Justice can seek relief from federal courts.

A separate criminal investigation by the FBI is under way and could lead to indictments of individual officers; Austin and U.S. Attorney David Fein would not comment on that probe. The East Haven police have drawn up contingency plans in the event that a number of police officers are indicted.

The investigation began in September 2009 in East Haven, a New Haven suburb where Hispanics and their advocates say police targeted them with traffic stops and false arrests. Latino business owners said rough treatment by police drove many newcomers from Mexico and Ecuador to leave East Haven.

At a news conference Monday at the U.S. attorney's office in New Haven, Austin said investigators encountered a "blue wall of silence" and efforts to interfere with and intimidate witnesses, which made it challenging to conduct the probe. There were references to "rats" within the police department in messages posted on a union bulletin board about the probe, the report said, and investigators learned Police Chief Leonard Gallo had warned staff that the Justice Department agreed to give him names of people who cooperated, which the department said was not true.

There was also a failure to fix the problem within the department, as well as a "deliberate indifference" to do so, Austin said.

Calls to Gallo were referred to the deputy chief, who did not return a message left at his office. Krebs said he could not comment on whether he thought Gallo or other top police officials should resign.

The East Haven Police Department of some 50 officers has come under scrutiny previously for civil rights issues. A federal jury ruled in 2003 that a white officer used excessive force and violated the rights of a black man he fatally shot after a chase. Some officers involved in that case kept their jobs and were promoted, and there was no evidence that anyone received training to prevent similar confrontations in the future, Austin said.

Republican Mayor Joseph Maturo, who took office Nov. 19, recently reinstated Gallo as police chief. Gallo had been on paid administrative leave since federal authorities began investigating last year. FBI agents had raided Gallo's locked office less than two weeks earlier.

The Rev. James Manship, a priest at St. Rose of Lima Church in New Haven, said the federal investigative report vindicates complaints made by Latinos of racial profiling. "Systemic reforms will be necessary to make sure the police department respects all residents," he said. "During his time as police chief, Gallo failed to take steps to improve the culture of the department. The DOJ's report makes clear that Chief Gallo is a primary reason for the department's failures, although his leadership is not the only problem."

Maturo's office did not immediately return a phone call Monday.

Paul Hongo, who was a deputy director to former Mayor April Capone, a Democrat who lost to Maturo last month and was at odds with the police department, said he believed the report was a vindication for his former boss. He said Capone wanted to say more about the problems in the department but could not because of the probe.

"Unfortunately, there were people in that community who led the charge and said this is all hogwash," Hongo said. "Well, as you can see today, it's not hogwash."