ATHENS, Alabama (WHNT) – An Elkmont teen, who is charged with killing five family members in September 2019 is set to go on trial next month, but the defense has raised a major issue that will have to be resolved before the trial.

Lawyers for Mason Sisk are arguing his statements to law enforcement should not be allowed in as evidence.

They argue in a court filing Tuesday that Sisk was not read his rights before being questioned.

Sisk is charged with killing five family members at their home in Elkmont when he was 14. Those killed include his father, John Wayne Sisk, 38; his stepmother, Mary Sisk, 35; and three siblings — a 6-year-old boy, Kane Sisk, a 4-year-old girl, Aurora Sisk and a 6-month-old boy, Colson Sisk.

The U.S. Supreme Court has ruled the Miranda warning, informing a suspect of their rights, is fundamental. That includes the right to remain silent, the fact that what you say can be used against you in court and that you have the right to an attorney. For juvenile suspects, the warning also includes the right to have a parent or guardian present as well. Investigators in Limestone County say Mason Sisk confessed to the killings, but the defense’s motion to suppress could mean that the alleged confession will be thrown out.

The defense motion to suppress comes five weeks before Sisk’s murder trial is set to begin.

Huntsville defense attorney Ron Smith, who isn’t part of the Sisk case, spoke to News 19 about the law surrounding Miranda warnings.

“Once the defense makes a motion to suppress statements the burden is then on the state,” Smith said. “The state is going to have to show a Miranda warning and they’re going to have to show that it was voluntarily made.”

The defense says Sisk’s recorded interview took place, but he was not read his rights.

“If the Miranda statement, or warning, was not given then whatever the defendant said can’t be used against him in the state’s case,” Smith said.

Investigators also said Sisk helped them locate the gun used in the killings

“And, if there is some evidence that was obtained from that statement … then that could probably still be used. If the statement is involuntary, then everything that’s directly caused or discovered because of the statement is out.”

The suppression hearing is scheduled for Aug. 12 in Limestone County Circuit Court.