According to the Alamance County Sheriff’s Office, Harris -- along with "a team of people" -- snuck into a mobile home park on April 8 to clean out a "stash house" used by the Cartel.
Harris allegedly entered the stash house first and captured one of the Cartel members, Alonso Beltran Lara.
Officials say Lara was subsequently tied up and shot twice in the head, execution-style.
At some point during the incident, officials say another suspected Cartel member entered the home and a gun battle broke out.
"It was almost like an old western shootout," Alamance County Sheriff Terry Johnson said.
"What was found was over 30-some shell casings in the trailer and outside the trailer, and three other mobile homes, in that particular park, with bullet holes in them."
When cops arrived at the scene, they found Harris shot to death in one of the bedrooms. He was wearing a bullet-proof vest and mask at the time. But, officials say his vest was no match for the high-powered weapons that were used against him.
Officials say they found Lara still alive and raced him to a hospital where he later died from his injuries.
Sheriff Johnson says investigators searched the crime scene and found 5 guns, roughly $7,000 in cash and more than a KILO of what they believe to be cocaine.
The concern now ... officials are VERY worried about violent retaliation from the Cartel.
"When we are dealing with the Mexican drug cartel ... somebody is probably gonna die as a result of this," Sheriff Johnson said.
"The Mexican cartels, they don't forget. They're gonna pay somebody back, somewhere and that concerns me."
Sheriff Johnson says he's puzzled as to how and why the Cartel decided to operate in North Carolina -- but says the goal now is trying to put an end to the drugs and violence.