A convicted killer who escaped from prison in Pennsylvania for days has been apprehended, ending a chase that had enthralled America and terrified residents of a Philadelphia suburb.

Danelo Souza Cavalcante, 34, escaped from Chester County Jail on August 31 while awaiting transfer to a state prison to fulfil a life term for fatally stabbing an ex-girlfriend in 2021. 

Prosecutors say he killed her to prevent her from informing police about a slaying in his home country of Brazil.

Mr Cavalcante was deemed to be exceedingly dangerous by U.S. authorities. There is a $25,000 prize on the table for information that results in his capture.

After escaping, Mr Cavalcante was intermittently spotted across the search area northwest of Philadelphia.

He broke into a garage on Monday, snatched a firearm, and ran as the homeowner grabbed a gun and fired at him, The Guardian reported. 

The public was urged to phone 911 if they saw Mr Cavalcante because police had issued warnings that he was now armed and should not be approached.

Mr Cavalcante was said to have scaled a wall by crab-walking up from the recreation yard, where he climbed over razor wire, ran across a roof and jumped to the ground. 

According to reports, his escape went undetected for more than an hour until guards took a head count. The tower guard on duty was fired, officials said.