A homeless man accused of fatally stabbing a Spring Valley security guard in 2020 has been declared incompetent to stand trial.

Authorities say 31-year-old Blanchard Glaudin was arrested for killing Sandra Wilson after she asked him to lower the volume of his headphones at Finkelstein Memorial Library. He pleaded guilty to second-degree murder in December.

On Friday, The Rockland County District Attorney’s Office announced that a judge found him incapable of understanding the charges against him due to mental disease or defect.

The decision halted sentencing date, which was scheduled for this week. Glaudin has since been placed into custody of the state Office of Mental Health and is receiving treatment.