The man accused of beating his grandmother to death while she was duct-taped to a chair last September has been found unfit to stand trial in his other attempted murder case.

Gary Bias was out on bail following the attempted murder of his stepfather, Ahmed Green, with a mini baseball bat in the fall of 2015 when he allegedly killed his 82-year-old great-grandmother Ella-Nae Bias at her home.

The 23-year-old did not appear in Brooklyn court Monday as it was revealed he’d been committed to a state facility for further evaluation and treatment.

His family was not present for the announcement.

Bias’ mother, Alisha Green, sprang him on $10,000 in 2015 after he failed to kill her husband, making way for the October 2016 bloodbath.

The unhinged man purportedly robbed his great-grandmother before binding and fatally beating her, cops said.

He then lured his mother to the scene, bound her to a chair, and attempted to kill her too, but she managed to escape.

Bias will return to court for a special hearing in April.