CHEYENNE, Wyo Armondo Ramirez- Serna admitted to the murder which took place in November of 2017.
Ramirez- Serna killed Justin Robinson, set his car on fire near Hereford Ranch, and ran to Nebraska.
Thanks to a police tip, he was caught six days later in Kimball.
Armando was charged with four counts for the crime, but with an agreement, he pleaded guilty to two of those counts.
The charges include robbery of a known drug dealer for money by threatening him with a gun, and use of a gun during violent crime, causing first degree murder.
In exchange for the pleas, the prosecution will not seek the death penalty, and advises he be sentenced to 40 years in federal prison.
U.S. Attorney Mark Klaassen feels this still reflects the seriousness of the crime.
"You know for this type of case, we felt that this was the appropriate resolution to give certainty not only for the conviction, certainty for the family but then again all the factors that are considered."
With the agreement, Ramirez- Serna is also waiving his right to any appeal.
he was in court Tuesday, but will be held in Scottsbluff jail until sentencing, which is scheduled for December.