Police suspected foul play when the pair was reported missing Feb. 16 because they couldn't find cell activity on either victim, Smith said, and immediately launched an investigation and search.
"When you lose a phone signal – two phones – when you lose that without any trace, in today's world, today's technology, that's why we jumped on it right away," Smith said.
Smith said earlier Monday that a tip had come in about Day's 2011 Chevrolet Camaro, which the two friends were last seen in when they left their Pearl River home. Investigators say Day and Hartline had been going to a relative's home in Kenner.
Day was found inside the car, shot in the front and back of the head, a coroner said. Hartline was found in the trunk, shot once in the back of the head. The bodies had a "significant" amount of decomposition due to the length of time they had been submerged, but they were positively identified through "very distinctive" tattoos, said the coroner, Chuck Preston.
Preston said investigators made the decision to move the car with the bodies still inside to the coroner's office before extricating the remains in order to preserve as much evidence as possible.
