Slain UPS Driver Shared Surprising Connection to Co-Worker Who Stalked & Shot Him 14 Times: DA

Expedito Cuesta De Leon was on the job when he was shot at 14 times; authorities say the connection between the victim and the suspect "is not something anyone of us can wrap our heads around."

Authorities investigating the shocking death of a UPS driver last week in Orange County have yet to uncover why he was killed, but they have discovered a surprising connection between him and his alleged killer.

50-year-old Expedito Cuesta De Leon ( above, left ) was driving his truck on the job on Thursday when he was shot and killed in an industrial park. According to a press release from the Orange County District Attorney , he was shot at 14 times, with 10 of those shots striking him. De Leon was in his truck, wearing his seatbelt and holding a UPS scanner when he was shot.

Woman Charged In Husband's Death After Wendy's Parking Lot Fight Over Nintendo Switch

The suspect in the shooting is 46-year-old Rhean Jalipa Fontanoza ( above, right ), who had been "on work disability" from the same company at the time of the shooting. Per the DA, he allegedly "stalked" his victim in advance of the May 16 shooting. Authorities also say they found evidence he asked another driver earlier in that day about De Leon's route.

But he didn't stop there.

District Attorney Todd Spitzer said, "When the driver told him De Leon had another route, Fontanoza is accused of going to the UPS Aliso Viejo substation where he was seen accessing a computer that shows driver routes and taking a picture with his phone."

It was two hours later that Fontanoza, allegedly lying in wait for De Leon, shot him "14 times in 19 seconds" as he was finishing up a delivery. Fontanoza was allegedly using a different car so De Leon wouldn't recognize him and had driven past him multiple times. He also reportedly wore a mask during the shooting, and then fled the scene.

Fontanoza was arrested about an hour later, but only after a standoff with a SWAT team and after a police canine and tear gas were deployed "into the vehicle," per prosecutors. He was then dragged out of his vehicle and cuffed, as seen in helicopter footage.

As authorities dug deeper into any connections between the two men, they quickly found a whole lifetime of them. As it turns out, De Leon and Fontanoza were allegedly childhood friends.

"Mr. De Leon was just going about his day, doing his job with no idea his longtime friend was stalking him with every intent to kill him," said Spitzer.

"The depravity involved to plot and carry out a plan to execute someone you shared a lifetime of memories is not something anyone of us can wrap our heads around," he continued. "No life should have to end like this and it is a tragedy that should have never happened."

Bodycam Footage Shows Moment Dad Accused of Forcing Son on Treadmill Before Death Is Stopped by Police

"We are assisting authorities however we can to understand what happened. As a result of the ongoing investigation to find those responsible, we are deferring any additional questions to authorities," UPS said in a statement, adding that "hearts are heavy tonight with the news."

"The safety and well-being of our employees is our top priority, and we are providing support and counseling services to our employees affected by this tragedy," they concluded.

Due to the particulars of the case, Fontanoza is facing one count of murder and special circumstances allegations of firing from a vehicle and murder by lying in wait, as well as a gun sentencing enhancement.

He is being held on no bail and if found guilty, he would be eligible for the death penalty.