A MURDERER has been found guilty of killing his 16-year-old niece who was reportedly pregnant with his child when she vanished.

Johnathan Quiles was convicted of murder on Thursday in the death of 16-year-old Iyana Sawyer, who left her Jacksonville, Florida, high school in December 2018 and was never seen again.

Eerie footage has surfaced of now-convicted killer Jonathan Quiles leaving his job on the day his niece vanished

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Eerie footage has surfaced of now-convicted killer Jonathan Quiles leaving his job on the day his niece vanishedCredit: Ace Pick-A-Part via WJXT
Quiles killed 16-year-old Iyana Sawyer in December 2018 after allegedly getting her pregnant

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Quiles killed 16-year-old Iyana Sawyer in December 2018 after allegedly getting her pregnantCredit: Jacksonville Sheriff’s Office
Iyana's body was never recovered and prosecutors believe she was dumped in a landfill

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Iyana's body was never recovered and prosecutors believe she was dumped in a landfillCredit: WJXT

Investigators say he stuffed her body in a dumpster though her remains were never found despite a landfill search in 2019.

On Thursday, a jury in Duval County found him guilty of murder and sexual battery after deliberating for an hour and a half.

A key piece of evidence presented to the court was eerie footage of Quiles' movements on the day that Iyana disappeared.

At around 11am, surveillance video from Ace Pick-A-Part, where Quiles worked, showed him leaving in a red minivan.

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He returned an hour-and-a-half later and was spotted using machinery to carry a vehicle out of the view of surveillance cameras.

It was the same day that Iyana was seen for the last time leaving Terry Parker High School.

Prosecutors believe that she was killed on the day of her disappearance and accused Quiles of putting her body in a car and dumping it.

Their theory was corroborated by Quiles' brother Joe, who testified that the killer tried to strangle his niece to death, but couldn't stomach it and shot her instead.

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But Gary Lindors, who helps run the junkyard, said it would be highly unlikely for Quiles to both move and process the same vehicles.

He did, however, confirm in court that Quiles was driving the minivan toward an area that was not used for employee parking.

The general manager of the Otis Road Landfill also testified in court and confirmed that Iyana's personal belongings, including underwear and high school textbooks, were recovered in his landfill.

The area is normally reserved for construction debris.

Other key witnesses in the case included Quiles' now ex-wife, who said she became defensive when the alleged sexual relationship came to light, but remembered an eerie change in his behavior upon reflection.

"Prior to that [Iyana's disappearance] he was fidgety, restless, nervous," Naomi Mobley told the court on Wednesday.

"After she went missing, he slept like a baby.

"I'm aware of this because I was very pregnant and was up every hour on the hour to go to the bathroom as he slept like a baby."

Johnathan's brother alleged that Johnathan told him he tricked Iyana into meeting him at the back of Ace Pick-A-Part.

He said Johnathan knew the exact time the dumpsters would be taken away, and dumped her body when it would be taken to a landfill, he told the court.

In a now-chilling text message presented to the court, Joe responded to Jonathan's alleged admission of guilt saying: "What you told me isn't a joke or something.

"If you was lyin', then you will be cleared and free, but if you wasn't, then you won't.

"Not the right thing for you and your selfishness. I hate to lose you, but I’d rather that girl’s family have some peace."

Iyana's family released a statement following the ruling and said a five-year nightmare has ended with justice.

"Johnathan Quiles has now been found guilty of murder and will go back before a jury to determine his fate on earth, but he chose to end Iyana’s young life," the statement reads.

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"He was a predator and the jury saw that with ease. We are grateful. Please keep our family in your prayers."

Quiles could face the death penalty for his crimes.

Quiles was convicted of murder on Thursday

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Quiles was convicted of murder on ThursdayCredit: WJXT
His brother testified that Quiles tricked Iyana into coming to the junkyard where he worked before killing her and dumping her body

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His brother testified that Quiles tricked Iyana into coming to the junkyard where he worked before killing her and dumping her bodyCredit: Ace Pick-A-Part via WJXT