An inmate who escaped from the Blair County Prison in early December is behind bars in Philadelphia. Officials say local police and U.S. Marshals apprehended and arrested 33-year-old Isaiah Tilghman, Friday at a gym in the city’s Port Richmond district. On December 3rd, Tilghman, who had been in custody for drug offenses and parole violations, reportedly climbed through a ventilation shaft to make his escape. Investigators say he’d been maintaining a low profile in Philly ever since. The U.S. Marshals Service reportedly has indicated that Tilghman was being held in an undisclosed correctional facility while waiting for his transfer back to the Blair County Prison.