Teen 'not sorry' for killing family after finding out mum is his stepmum

Mason Sisk has been charged with the murders of his parents and siblings. Photo / Limestone County Sheriff's Officer

A 14-year-old boy who allegedly shot his parents and three young siblings has shown no remorse.

The teenager allegedly murdered his whole family after he found out his mother was actually his stepmother.

Mason Sisk, from Alabama in the United States, faces adult capital murder chargers for the deaths of his parents and siblings in September last year.

According to Limestone County chief juvenile probation officer Tara Pressnell, "Mason does not seem bothered by the fact that he is accused of murdering his family".

"He has not shown any sign of remorse. While in detention, he has not talked about his family at all," Pressnell added.

Sisk has been charged with five counts of capital murder.

Mary and John Sisk were respected and loved members of their community. Photo / Supplied

Investigators believe the teen shot his family after discovering that Mary Sisk, 35, was not his biological mother.

He is alleged to have shot her, along with his dad, John Sisk, 38, and his siblings Grayson, 6, Aurora, 5, and Colson, who was only 6 months old.

A judge last week ruled there are "no reasonable grounds" to declare the teenager mentally ill.

Sisk reportedly initially blamed the shootings on someone else but it is claimed he has since confessed.