Investigators from the U.S. Justice Department say that East Haven police have discriminated against Latino residents, the Associated Press reported Monday.

Between one third and one half of drivers pulled over by certain East Haven police officers in 2009 and 2010 were Latino, the investigators found, while Latinos make up only about 10 percent of the area’s population. They also discovered that Latinos faced harsher punishments for minor violations than did non-Latinos, and that at least once an officer looked up a moving car’s insurance information to find a reason to stop it.

“No matter how we looked at it, we found problems,” said Roy Austin Jr., deputy assistant attorney general for the Justice Department’s civil rights division. He said certain police squads pulled over an “extraordinarily high” number of Latinos.

The investigation started in September 2009, when Latinos in East Haven claimed they were being unfairly targeted by police. Austin said he and other Justice Department officials were confronted by a “blue wall of silence” from the police department and attempts to interfere with witnesses — for example, he said Police Chief Leonard Gallo told staff that he would be able to learn the names of people who cooperated with investigators.

Austin said he saw a “deliberate indifference” to fixing the problem among East Haven police, but he added that the Justice Department will reach out to police and local officials to push for reform. The FBI is conducting a separate investigation that could lead to criminal charges for individual officers.

Gallo was recently reinstated as police chief by East Haven Mayor Joseph Maturo, who took office last month. Gallo had been on paid administrative leave since last year, when the Justice Department issued a preliminary report of its investigation.