When sheriff's deputies arrived at the house they found Vargas laying in the front yard with several stab wounds to his upper body. He was transported to Loma Linda Medical Center, where he later died from his injuries.
Vargas had just returned from Iraq and was about to be deployed to Afghanistan for his second tour of duty.
On Sunday deputies arrested 20-year-old Matthew Duronio of San Bernardino, who is being held without bail.
Authorities say Duronio led them to one of two vehicles seen leaving the scene of the stabbing. They're still looking to question another man who drove off in a black SUV with tinted windows and a white sticker on the lower left corner of the rear window.
If you have any information on the stabbing, you're asked to call the San Bernardino County Sheriff's Department at (909) 387-3589.
MORE LOCAL HEADLINES FROM INLAND EMPIRE
SEND TIP || REPORT TYPO || TWEET @abc7 || WIDGET