San Diego Police, who are working with Mexican authorities on this case, say he had been stabbed to death.
Shane was last seen by his employer the night of Saturday, March 21, when he asked to take a truck so he could work an extra shift on Sunday.
Shane's employer repeatedly tried to reach him after they didn't hear from him for a few days, but his cell phone was turned off.
The company reported the truck stolen with Anaheim police. It was still missing as of Monday.
Shane's boss wants to know what happened to him and who is responsible.
"He was just a wonderful kid. He was like my son. We treated him that way," said Gayle Boan, Shane Pennington's employer. "Whoever is out there -- Somebody knows something about what has happened to him and I want to help. I want him found. I want that person found. He didn't deserve to die."
Pennington had moved out to Anaheim from North Carolina. At times he lived with family friends in Redlands. Other times he rented a motel room.
San Diego authorities say they have no suspects in the case and no motive for Pennington's murder.
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