The defense focussed in on statments made by first responders that Chambers stated on the scene that someone named "Eric" had set her on fire.
He added that Mr Tellis repeatedly lied to investigators about spending time with her in the hours before she was found.
A longtime firefighter said Wednesday he had never seen a victim so badly burned when he found a young MS woman lying on the ground - barely able to sleep with blisters covering her body - before she died after being intentionally set on fire.
Lisa said she believes "somebody was with" her daughter during their phone conversation, according to local TV station WMC. She said all three of them hung out that morning to smoke marijuana for one to two hours before they dropped Tellis off near a grocery story on Highway 51.
"Horrific burns", Mr Champion said.
He claimed to have been buying a pre-paid debit card at the time Chambers was killed, but prosecutors believe he intentionally went to the store after setting the woman and her auto on fire to create an alibi for himself, The Clarion-Ledger reported.
Cole and another firefighter, Brandie Davis, told jurors Wednesday that Chambers responded "Eric" when they asked who had set her on fire.
"I think he suffocated her", Champion said.
Cristina Corbin is a Fox News reporter based in NY.
Quinton Tellis faces life in prison if convicted in the 19-year-old's death almost three years ago in Courtland, Mississippi, but has maintained his innocence in the case. "I asked, 'Who did this to you?' She replied, 'Eric.' I asked again, 'Baby girl who did this?' and she replied, 'Eric, '" Davis said, reading his statement in court.
Champion acknowledged Chambers gave a name to first responders that does not match Tellis', but said by the end of the trial, the evidence "will change your mind, I can promise you".
Tellis' lawyer Darla Palmer was up next.
Palmer also stressed the apparent discrepancy of Jessica's description of her killer. "She didn't say any other name, she didn't mention any other person".
"He insisted this is not something he would do", Palmer said.
Tellis was serving time in Ouachita Parish Jail in Monroe, Louisiana, at the time of his indictment in Chamber's murder last year, where he was being held on charges connected to the brutal stabbing death of 34-year-old Meing-Chen "Mandy" Hsiao.
Authorities analyzed over 20,000 telephone numbers as part of the investigation and 40 people are listed in court documents as potential witnesses in the trial, WREG reported. No trial date has been set in that case.