On Monday, Iron County Sheriff's Detective Jody Edwards said Derek Davis and Chad Grijalva, both 34, suffered multiple gunshot wounds to the head and torso.

It appears the killings took place on Oct. 24, the same day the victims were reported missing, he said.

The bodies were unearthed Saturday, a day after deputies went to the residence of Martin Chris Nelson to arrest him on suspicion of failing to register as a sex offender, a third-degree felony.

Nelson is a suspect in the killings, but he has not been charged. The 43-year-old is being held in the Iron County Correctional Facility in Cedar City.

He made an initial court appearance Monday afternoon on charges of failure to register as a sex offender and possession of a controlled substance, both third-degree felonies.

Iron County Attorney Scott Garrett said Monday his office is still screening the homicide cases and will decide in a few days whether to charge Nelson with the killings.

Deputies investigating Nelson in the failure to register case searched unsuccessfully for him in September after receiving word he was living in the Beryl area, a remote community of sagebrush interspersed with large alfalfa fields about 50 miles northwest of Cedar City, Edwards said.

They renewed their search after hearing Nelson might have a connection to one of the missing men, according to Iron County Sheriff Mark Gower.

It appears Grijalva knew Nelson and went to his residence near 2400 West and 6000 North on Oct. 24, possibly to collect a $500 debt for some tile work, Edwards said. Davis apparently drove Grijalva to meet Nelson.

Police discovered Davis' white, 1994 Ford Ranger Friday at Nelson's residence while they were investigating the failure to register case. They began searching the area after obtaining a warrant.

The bodies were found buried in the earthen part of a shed used to store hay and other types of feed for horses, the detective said.

According to court records, Nelson pleaded guilty in September 2005 to charges of domestic violence and drug possession.

In 1992, he was convicted on four counts of child molestation, according to the Utah Department of Corrections.

mhavnes@sltrib.com