A 21-year-old Cheyenne man accused of shooting a 19-year-old man in the head and dumping his body in a reservoir has been bound over to Laramie County District Court.

Armando Ramirez-Serna was facing charges of first-degree murder, attempted robbery and third-degree arson in the death of Justin Robinson, but the state on Friday amended the charges to second-degree murder and property destruction.

According to preliminary hearing testimony, Ramirez-Serna reportedly told 17-year-old Angelo Trujillo -- an alleged accessory -- that he was going to rob Robinson, but things went sideways so he had to shoot him.

Robinson was found floating face down in a reservoir on the Wyoming Hereford Ranch Nov. 26. His burnt SUV was found nearby.

Ramirez-Serna and his girlfriend, 19-year-old Raquel Rodriquez, were arrested approximately one week later at the First Interstate Inn in Kimball, Nebraska.

Ramirez-Serna continues to be held in the Laramie County jail without bond. If convicted of second-degree murder, he could face 20 years to life in prison.