Quinton Tellis, a 27-year-old Louisiana man, was indicted on capital murder charges on Tuesday.
"We knew he was the last person she was with," Desoto County District Attorney John Champion tells PEOPLE. He adds that Tellis is "what we call a habitual offender."
Champion says authorities zeroed in on Tellis when they got information on the location of his phone: "We came to the realization that he was with her at 6 o'clock. Their phones were absolutely together in Batesville," he says.
He adds, "We found out he was in Louisiana in jail down there and one thing led to another, and he kept lying to us, and every time we'd bust his lies, he'd change his story, and he basically put himself with Jessica until 7:26. We know she was on the scene until 7:31. So the chances of her being with somebody else for 4 minutes just doesn't make sense."
Champion would not speculate on a possible motive. He says that he thinks Tellis acted alone.
Jimmy Alford Studios
Ouachita Parish Sheriff
He adds that Tellis is being held in Louisiana for unlawful use of a credit card, which belonged to a Chinese exchange student who was murdered.
According to Champion, Tellis was filmed on surveillance camera using the debit card of the student. "They've got a really good circumstantial evidence case on that murder down there, but they have not charged him on that yet," he says.
Authorities have said Tellis and Chambers grew up in the same neighborhood.
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Tellis has not yet entered a plea to the charges related to Chambers.
Authorities plan to release more information about Tellis and Chambers in a press conference on Wednesday morning.
With reporting by ALEXANDRA ROCKEY FLEMING