(Ted S. Warren/AP)

A group of Massachusetts state troopers who patrolled the turnpike were directed to issue a certain number of tickets while on duty or risk losing out on lucrative overtime shifts, federal prosecutors said.

The overtime abuses were linked to special patrols designed to catch speeders on Interstate 90. Members of Troop E, which has since been disbanded, had to write at least eight tickets per shift despite repeated agency denials of the practice and state court rulings that such quotas are unconstitutional, the Boston Globe reports.

The quotas came to light in a sentencing memorandum filed last week for former trooper Eric Chin, one of dozens of troopers under investigation for fraudulently pumping up overtime payments from special patrols.

Chin, a 15-year veteran of the force before his suspension, pleaded guilty to embezzlement after receiving pay for overtime shifts he did not work or from which he left early, federal prosecutors said. Chin made $302,400, including about $131,653 in overtime, of which $7,125 was for hours he did not work, according to the sentencing memorandum filed March 13 in U.S. District Court by assistant U.S. Attorneys Mark Grady and Dustin Chao.

Chin and other troopers who signed up for extra shifts would write the minimum number of tickets, often in an hour or less, and go home, the memo says. It also says that if the weather was bad, the troopers would simply call it a day, even though the policy required that they be diverted to other duties during their shifts. Instead, the troopers treated inclement weather like a “snow day” and abused the safety program as if it were a “paid holiday,” the memo says.

Eight troopers in total have been charged with defrauding an agency that received federal funds, and seven have pleaded guilty or agreed to plead guilty, federal prosecutors said. The special patrols — known as the Accident and Injury Reduction Effort (AIRE) — were designed to beef up patrols on the Massachusetts Turnpike.