A 22-year-old Cheyenne man was sentenced in federal court Monday to 40 years in prison for killing a 19-year-old Cheyenne man while robbing him of marijuana and cash.

Armando Ramirez-Serna pleaded guilty on Oct. 9 to interference with commerce by robbery and use and discharge of a firearm during and in relation to a crime of violence causing death as part of a plea agreement.

In exchange for his plea, two other counts were dismissed at sentencing.

Authorities say Ramirez-Serna killed Justin Robinson in November 2017, dumped his body in a reservoir on the Wyoming Hereford Ranch and burned his SUV.

Ramirez-Serna was also ordered to pay over $19,000 in restitution to Robinson's family and to the Wyoming Division of Victims Assistance.