A key witness in the case against a South Dakota serial killer is back in jail facing up to another two years in prison for violating his supervised release in an unrelated case.

Jeremy Brunner pleaded guilty to passing a counterfeit $100 bill at a Sioux Falls casino and was sentenced in March 2008 to one year and a day in federal prison.

Prosecutors say he recently acknowledged violating the
conditions of his release by drinking alcohol, failing to take part
in a Pennington County work release program and not participating
in a substance abuse program.

Brunner was an informant for the state in 1997 in its
investigation of Robert Leroy Anderson, who was sentenced to death
for killing two women. He committed suicide in prison in 2003.