FARMINGTON — A Shiprock man who pleaded guilty in federal court Monday to a role in an armed robbery that left the alleged thief dead could face more than four years in prison.

Neilson McKensley, 49, will be sentenced to 46 to 57 months as a condition of a plea agreement, which required him to plead guilty to an armed robbery charge, according to a U.S. Attorney's Office news release.

In the early morning hours of Oct. 27, 2012, McKensley and Randy Coolidge, 46, tried to rob Vernon Atcitty's home on Mesa Farm Road in Shiprock, according to the affidavit for McKensley's arrest.

McKensley drove Coolidge to Atcitty's home and Coolidge entered armed with a .22 caliber pistol and black duct tape covering part of his face. McKensley said in court documents that he knew Coolidge planned to rob Atcitty.

McKensley told FBI investigators that he heard a fight inside Atcitty's home and then heard two gunshots. Coolidge was shot twice and died.

His body was found on Mesa Arms Road a couple hours later. Atcitty told investigators he tried to drive Coolidge to Northern Navajo Medical Center but his body fell out of the truck.

McKensley has been in federal custody since his Nov. 13 arrest.

Ryan Boetel can be reached at; 505-564-4644. Follow him on Twitter @rboetel.