PORTLAND, Maine (AP) — A study by the American Civil Liberties Union of Maine shows that taxpayers are spending tens of thousands of dollars a year to jail low-income offenders for failure to pay fines or make restitution payments.

The Portland Press Herald reported that the study shows nearly 10 percent of inmates booked into the Cumberland County Jail between August 2013 and August 2014 were there solely because they missed court-ordered payments.

Grainne Dunne, who led the study, says booking records collected from 12 of the state’s 15 county jails mirror statewide the findings in Cumberland County. She said the information had to be compiled by hand from booking records.

“We found thousands of people that they booked just on failure to pay fines,” she said. She said at the 12 jails researchers studied for the one year period, more than 3,000 inmates were booked for failure to pay fines or make restitution payments.

One example cited in the study is the case of Conner Comeau, who was convicted in 2010 of spraying graffiti on rail cars at a South Portland train yard and was ordered to pay $1,300 in restitution. When he missed two payments in 2014, he ended up in jail for 100 days, at a cost of about $11,200 to incarcerate him house him. Cumberland County Sheriff Kevin Joyce said the state recouped none of that cost.

Cumberland District Attorney Stephanie Andersons tells the newspaper she doesn’t believe the poor are being targeted. She says judges often are bound by mandatory, minimum fines set by the legislature.

“I think the fines tend to be awfully high,” Anderson told the newspaper. “We need to come up with some way where people can provide some sort of community restitution in lieu of fines.”