Mark Santiago Gaughan was 23 and described as a model who dreamed of joining the military and becoming a pilot. He was the only child of his mother, Caroline, with whom he had reportedly made a pact after his father died to always stick together.

In the pre-dawn hours of August 23, 2025, less than an hour after texting his mother that he loved her, Gaughan was found on the sidewalk of a Nassau Drive home in Las Vegas with gunshot wounds to his neck and torso. He was pronounced dead at the scene; the coroner ruled his death a homicide. Investigators say he had been taking Polaroid photos of his girlfriend of six months, 20-year-old Allysandra Blea, and a friend. Police recovered Polaroids showing Blea holding a gun and another woman holding a knife. Witnesses told detectives Blea had been holding or pointing the weapon at Gaughan immediately before a shot was fired, while another acquaintance said he had unloaded the gun earlier because the group was drinking. Detectives also reported finding social media messages from Blea expressing strong interest in firearms and violent statements.

Three days after the killing, police arrested Blea and charged her with open murder with a deadly weapon. If anyone knew Mark, his circle, or was in that neighborhood the morning of August 23, please come forward with what you remember.