PEARL RIVER- It's the image he dreaded seeing, one that made Russell Hartline slam on his brakes while traveling on Highway 90 last Monday. Hartline was headed to the East Pearl River Boat Launch after hearing that his son's body had been found, submerged under water.

"On my way there coming the other way on the highway was all the sheriff's vehicles and then the tow truck with the vehicle on the back of it," Hartline said.

Inside the trunk of the 2011 Chevy Camero lay his son, 20-year-old Dustin Hartline, who was shot in the back of the head.

Also in the interior of the car, was his friend, 20-year-old Reagan Day, who was shot twice in the head.

"That was kind of tough to see," Hartline said.

Hartline and Day were last seen on February 15 in Pearl River. They were on their way to Kenner before heading to a doctor's appointment in Baton Rouge.

After days of endless searching and leads, a tip led investigators to the East Pearl River Boat Launch on Highway 90. The next day, four people were taken into custody.

"This was a carjacking gone bad. These four individuals who were arrested for first-degree homicide, had plan this, premeditated this," St. Tammany Parish Sheriff Randy Smith said.

This is sadly not the first loss to hit Hartline. He lost his youngest son and Dustin Hartline's brother, Dalton Hartline in 2016.

"He actually passed on Dustin's birthday. Which kind of added to the pain," Hartline said.

The pain remains unbearable. Now, Hartline can only look towards the future, seeking justice for his son.

"If I'm not mistaken, in Louisiana, first-degree murder, does warrant the death penalty. And I would hope that the DA is going to push for that, for the four suspects that were directly involved," Hartline said.

As they prepare for Dustin Hartline's funeral, Russell Hartline does so knowing he won't give up on his child, seeing this case through until the very end.

"We'll be there. We'll be there in the courtroom. And uh, we'll be keeping an eye on what's going on with that to make sure they're held accountable," Hartline said.

A go fund me account has been set up for funeral expensive. If you'd like to donate, go to https://www.gofundme.com/dustinhartline.