Investigators say a missing inmate was found Thursday hiding in the ductwork of the Middlesex County Jail.

Officials discovered an injured man Thursday morning in the ductwork using thermal imaging. Investigators say that man was the missing inmate, 20-year-old Timothy Petties.

Petties failed to turn up for a head count Tuesday at the jail. Officials conducted searches throughout the day, but were unable to find him. According to officials, there were no signs of a breakout.

Petties has been at the jail for a month as he awaits a trial on charges of resisting arrest and aggravated assault. Authorities plan to beef up Petties' rap sheet with escape charges.

Petties' family members don't understand how escape charges could be filed since the man never left the premises. They also say they're upset at not being able to see or talk to Petties since he was found.

Related information: Inmate disappears from Middlesex County jail