On April 21, Elvis Zachary Olsen, 22, was found shot to death near Fort Duchesne on the Uintah and Ouray Indian Reservation, and his 2011 Mazda 3S was gone.
When Uintah County Sheriff Jeff Merrell and a detective caught up to Saenz in Arizona on April 24, they said they found him driving Olsen's Mazda. He waived extradition and was brought back to Utah and booked into the Uintah County Jail.
Uintah County Undersheriff John Laursen said Friday that investigators have not been able to establish a motive for the slaying, adding that Saenz was not being cooperative with police.
Saenz is scheduled to make his first court appearance for the murder charge on Tuesday before Judge Clark McClellan. The same day, he's scheduled for a hearing relating to his pending rape trial, which is set for July.
In that case, Saenz faces charges of aggravated sexual assault, aggravated kidnapping, forcible sodomy, object rape and forcible sexual abuse, all first-degree felonies.
Saenz followed a woman home on a shuttle bus from a nightclub early June 10, 2012, according to the charges. Once they got off the bus, he punched her twice and dragged her across a street to a spot outside an apartment complex, where he raped her and broke her cellphone, charges state.
As part of his bail conditions for the rape case, Saenz was ordered to wear an ankle monitor. Laursen said Saenz cut the ankle monitor in the Roosevelt area on the day of Olsen's death.
Saenz and Olsen, who was a convicted sex offender, were believed to be in the Uintah County Jail at the same time, but they did not share a cell, according to Uintah County Undersheriff John Laursen.