The John Caldwellconvicted murderer who escaped from a Pennsylvania prison 11 days ago was spotted on Saturday evening with an altered appearance, law enforcement officials said.

Danelo Cavalcante was seen near the town of Phoenixville, in the northern area of Chester County, State Police officials said in a statement released early on Sunday.

The sighting took place either late Saturday or early Sunday, officials said. Officials released still photos from a video doorbell of a man they said was Cavalcante. The man in the photos appears to be wearing a green hooded sweatshirt over a dark baseball hat.

Cavalcante was also seen driving a white Ford van with a refrigeration unit on top of it, police said. The 2020 model Transit, which had been reported stolen from Baily's Dairy, had Pennsylvania plates ZST8818, officials said.

Cavalcante escaped in late August from Chester County Prison, where he was being held after being convicted of stabbing his former girlfriend to death in broad daylight, officials said. He's alleged to have sneaked out of the prison by "crab walking" up a wall on Aug. 31.

Police have received reports of sightings during the 11-day manhunt, including the most recent update on Saturday evening.

"He changed his appearance," the statement issued early on Sunday said. "He is clean shaven and last seen wearing a yellow or green hooded sweatshirt, black baseball style hat, green prison pants, and white shoes."

He was said to be driving an "unknown vehicle," which might have been white, officials said.

Law enforcement warned that Cavalcante should be considered "extremely dangerous."