BISMARCK, N.D. (AP) - A new report shows that a North Dakota college student who was found dead in a river last year was working for a regional drug task force as a confidential informant a few months before he died.

The independent state review also concluded that the drug task force handled its dealings with 20-year-old Andrew Sadek properly.

Sadek went missing from the State College of Science in Wahpeton in early May 2014. His body was found in the Red River in late June. An autopsy concluded he died of a gunshot wound to the head. His death is still being investigated.

Mother Tammy Sadek says she questions whether her son was pressured into working for the task force. She believes her son was murdered.