LIMESTONE COUNTY, Ala. (WHNT) — The Elkmont teen convicted for killing five of his family members in September 2019 has filed a motion to have his case retried.

A jury found Mason Sisk guilty on four counts of capital murder in April and a judge sentenced him to life in prison without the possibility of parole. Now, the 18-year-old is asking to have his case retried based on several issues that were ruled on by the court prior to his previous trial.

According to court documents, Sisk wants the statements made to law enforcement officers the night of the crime suppressed. This issue was brought to the court before his April trial, but the defense’s motion to have these statements suppressed was denied.

The judge’s ruling allowed prosecutors to show the jury Sisk’s interview with investigators — including former Limestone County Sheriff Mike Blakely — the night of the killings. During that interview, investigators pushed Sisk to describe what happened and he insisted for an extended period that he was downstairs playing video games, heard a noise and then ran upstairs and saw a car driving away.

He said he called his girlfriend before calling 911.

At one point, he told investigators he didn’t check on his family because he assumed they were dead. Blakely expressed skepticism over Sisk’s account and the teen eventually said, “I did it.” He didn’t provide details of the shooting.

At the time, the defense argued the recording should not be allowed into evidence because Sisk was held in custody for more than an hour by deputies and asked questions, without being read his Miranda rights. He was also questioned without an adult being called to sit in on his interview.

The defense made the same argument in court documents filed on October 6.

Sisk’s legal team believes that the lack of suppression of statements affected the outcome of the trial. Court documents also show that Sisk’s argument for a new trial involves another issue that was denied before his April trial.

The court denied the defense’s attempt to call Dr. Jeffery Neuschatz as a witness on the subject of coerced confessions, but the prosecution argues he is not an expert in that area. The judge previously ruled that this testimony be excluded and that ruling was upheld in April but Neuschatz was allowed to speak in court in case of a possible future appeal.

However, that testimony was not in the presence of the jury and is one that the defense argues would’ve had a significant impact on the outcome of the trial.

The third argument for retrial that Sisk’s defense brought to the court was the prevention of alternate suspects and family dynamics being presented to the jury in the April trial.

In Sisk’s first trial, the defense was allowed to present testimony regarding the paternity of the youngest Sisk child, with the court ruling that the issue of paternity was admissible. However, prior to the April trial, it was found “immaterial, irrelevant and because any probative value of such statements is substantially outweighed by the danger of unfair prejudice,” and testimony on the issue of paternity was not allowed to be introduced.

Sisk’s defense believes this testimony being excluded did not allow them to present reasoning regarding the theory of an alternate suspect and in turn, did not allow for Sisk to receive a fair trial.

The final argument for a new trial in the defense’s filing was the admission of jail messages to the April trial.

While in jail, Sisk used a device to message his ex-girlfriend and jurors were shown text messages between the two. In those text messages, Sisk tells the ex-girlfriend that he committed the crimes but was held at gunpoint and forced to shoot the five victims.

The defense argued that due to his age, Sisk could not consent to the contractual terms necessary to possess this device and was not properly advised that the messages were being recorded for use by the prosecution.

Currently, Sisk is serving a life sentence at Kilby Correctional Facility in Montgomery.