MISSOULA (AP) — Montana has had more corruption prosecutions than any other federal court district in the nation in recent months, mainly because of an effort to target fraud in tribal programs, the state’s U.S. Attorney’s Office says.

According to a study from a Syracuse University-affiliated research group, 18 people were prosecuted on federal corruption charges in Montana between October 2013 and April 2014. No other federal judicial district in the nation had more than 15.

A news release this week from the Montana U.S. Attorney’s Office, which prosecutes crimes in the state’s federal court system, cited the study’s findings as stemming from the success of its Guardians program, which targets fraud and official abuse involving federal funds.

Assistant U.S. Attorney Carl Rostad said the effort is a collaboration between federal prosecutors in his office, the FBI and the IRS, established in October 2011 in response to concerns over fraud in the spending of federal stimulus funds provided in 2009.

As a result of those concerns, fighting corruption has become a focus for Montana’s federal attorneys, Rostad told the Missoulian (http://gftrib.com/1kiBZfm).

He pointed to a case involving the siphoning of funds for a $33 million water project on the Rocky Boy’s Reservation as an example.

Compared to violent crime cases, where investigative work focuses on interviewing witnesses and gathering physical evidence, white-collar crime investigations involve pouring over financial information like bank account records to untangle complex plots.

“They’re very document-intensive, very time-intensive,” Rostad said. “An incredible amount of green eye-shade work.”

In the news release, U.S. Attorney Mike Cotter, the chief federal prosecutor for Montana’s judicial district, lauded work done by federal investigators.

“Their efforts have unearthed widespread criminal activity and flagrant abuses of trust with regard to federal programs and grants designed to provide for the common good of our Indian communities,” Cotter said.