Grand Rapids police have been able to close the books on a nearly 10-year old unsolved murder after a man behind bars in a federal prison in Pennsylvania admitted to the crime.

33-year-old Walter Wilson has pleaded guilty to second-degree murder as a habitual offender. In return, Kent County prosecutors dropped a perjury charge.

26-year old Robert Farmer was shot to death during a robbery outside a party store on the city's southeast side on October 15, 2004.

Police detectives with the Grand Rapids Cold Case Team used "witness statements, tips and DNA evidence" to link the crime to Wilson, who has been in a Pennsylvania federal prison serving a minimum of 15 years for possession of illegal weapons stemming from a 2007 case.

Wilson faces a minimum sentence of 25 years in prison when he is sentenced August 13.