The suspect in the stabbing death of a 27-year-old in West Jordan was apparently the victim’s childhood best friend, who police allege lashed out because he believed the victim was having sex with his girlfriend.

The confrontation took place around 4 or 5 a.m. Tuesday outside a home near 9250 South and 3825 West.

According to a probable cause statement, Adam D. Cross and his girlfriend were at a gas station getting drinks about 30 minutes earlier when Cross started arguing with someone on the phone. Cross apparently told the person to “come at me.”

The couple then drove to a home, and Cross’s girlfriend went inside to put the drinks away. When Cross’s girlfriend returned outdoors, she saw Cross and another man fighting in the street.

Cross’s girlfriend said she saw the suspect hit Cross in the head with a bat and that she saw the suspect pointing at the victim with a knife. Cross told her he needed to go and was “bleeding out.”

She said the suspect accused Cross of having sex with the man’s girlfriend, according to the probable cause statement. Cross’s girlfriend then took him to a hospital, where he collapsed and hit his head again.

At the hospital, medical staff found Cross had been stabbed twice and one of his lungs had collapsed. He died as crews prepared to put him on a helicopter to another hospital.

Police linked the stabbing to the suspect after speaking with Cross’s twin brother, who said the suspect was one of Cross’s best friends when they were growing up. Investigators tracked the suspect to a home in West Jordan. The suspect came outside and police took him into custody.

When police searched him, they found a knife with what appeared to be blood residue on the blade. The suspect allegedly told police that he fought with Cross, hit him with a bat and had “impale[d]” him. The man said he’d learned about his girlfriend’s alleged relationship with Cross earlier, and witnesses said he then “was in a rage.”

The alleged assailant was booked into Salt Lake County jail. He is accused of first-degree felony criminal homicide and second-degree felony obstruction of justice. He has not yet been charged.