
PHILADELPHIA (WPVI) -- Police are searching for a masked suspect whom investigators say has been terrorizing people in Center City Philadelphia.
Video released by police Monday shows a masked man chasing a woman who was jogging near City Hall last Wednesday around 5:30 a.m.
"He was holding his cellphone in front of her, at which point he asked her, 'Are you ready to die?'" Philadelphia Police Capt. Jason Smith said.

Police said the startled victim attempted to flee.
"The female is screaming for help this entire time," Smith said. The "male abruptly stops and heads northbound on 15th Street, at which point he gets on the escalators at Suburban Station."
Kate Egan told Action News that the same suspect terrorized one of her coworkers at a coffee shop that same morning. A security guard at the business intervened.
Both victims were able to get away unharmed.
"It's pretty disturbing," Egan said.
The incidents have left Egan and others concerned.
"It's really unsettling just trying to get to work and have a kid like this actively terrorizing women," Egan said. "I really hope he is caught."
Investigators believe the suspect is between 16 and 20 years old.
Police said the suspect allegedly implied he had a weapon at one point, although no weapon was ever seen.
Authorities said the suspect is facing charges including terroristic threats, harassment, simple assault and intimidation.
Anyone with information is asked to contact Philadelphia police by calling 215-686-TIPS (8477).