Authorities searched today for escaped murderer Danelo Souza Cavalcante who has eluded capture since breaking out of a southeastern Pennsylvania prison a week and a half ago after he apparently slipped through a search perimeter, changed his appearance, stole a dairy delivery van and contacted acquaintances.

Chester County residents were asked to be on the lookout, check their security cameras and keep vehicles and homes locked as the search for Cavalcante continued, state police said on social media this morning.

Lt. Col. George Bivens of the Pennsylvania State Police said Sunday that Cavalcante stole the unlocked van, which had the keys inside, sometime Saturday night. The van had been parked at a dairy farm about three-quarters of a mile from the northern perimeter of the search area where hundreds of law enforcement officers had been looking for him.

Bivens vowed to “aggressively continue” the search and said he is confident the fugitive will be captured.

He declined to say how he thought Cavalcante slipped through the perimeter, but said it had weaknesses, such as underground tunnels and huge drainage ditches, and that no perimeter is 100% secure and no operation goes according to plan.

“That happens in investigations, it happens in manhunts, it happens in all kinds of things,” said Bivens, who also helped guide a 48-day search for cop-killer Eric Frein in 2014. “That’s why if you’re smart, you’re planning contingencies and you’re ready to adapt to whatever happens. This is a minor setback. We’ll get him. It’s a matter of time.”

Cavalcante’s sister was arrested by immigration authorities, Bivens said. The matter involved “immigration issues,” he said, but declined to provide specifics, including the date of the arrest. U.S. Immigration and Customs Enforcement did not immediately respond to an inquiry about it today.

Bivens said state police are authorized to use deadly force if Cavalcante isn’t actively surrendering.

Other agencies involved in the search may have their own rules, he noted.

Several law enforcement agencies put more stringent requirements in place for preauthorization of different levels of force in the wake of national protests and calls for policing reforms after the killing of George Floyd by police.

The Pennsylvania State Police regulations republished in July outline specific scenarios where deadly force is justified including to prevent the escape of someone who has committed a violent felony such as murder and who could pose a threat to the community.

By preauthorizing the use of deadly force for troopers if Cavalcante does not surrender, state police officials are eliminating a potential delay.

Some schools in the region planned to hold outdoor activities inside. Owen J. Roberts School District in Pottstown announced that there would also be an increased security presence at its schools today, including local law enforcement officers.

Baily’s Dairy said on its Facebook page that the delivery van was stolen between 7 p.m. and 10 p.m. Saturday “while we were still here working.” Police contacted them after 5 a.m. with news of the theft.

In the meantime Cavalcante, 34, traveled more than 20 miles (30 kilometers) northeast to East Pikeland Township and Phoenixville. Shortly before 10 p.m. Saturday he went to an East Pikeland Township home of a person he had worked with several years ago and asked to meet with him, police said.

The homeowner, who was at dinner with his family, spoke with Cavalcante but did not respond to his request to meet. He called police after returning home and reviewing his doorbell video.

Shortly after 10 p.m. Saturday, police said, Cavalcante went to the Phoenixville area home of another former work associate, who wasn’t home, police said. An investigation into that encounter produced information about the van that Cavalcante stole, Bivens said.

Doorbell video images showed Cavalcante to be now clean-shaven and wearing a bright green hooded sweatshirt, police said. The stolen van was found at 10:40 a.m. Sunday in a field behind a barn in East Nantmeal Township, about 15 miles (25 kilometers) west of Phoenixville.

Bivens said he believed Cavalcante abandoned the vehicle at least in part because it was low on fuel.

Cavalcante, 34, escaped from the Chester County Prison while awaiting transfer to state prison on Aug. 31 after being sentenced to life for fatally stabbing his ex-girlfriend in 2021. Prosecutors say he wanted to stop her from telling police that he’s wanted in a killing in his home country of Brazil.

To escape, Cavalcante scaled a wall by crab-walking up from the recreation yard, climbed over razor wire, ran across a roof and jumped to the ground. His escape went undetected for more than an hour until guards took a headcount. The tower guard on duty was fired, officials say.

Authorities had tracked him to an area around the Longwood Gardens botanical park, where police had about 400 personnel, including tactical teams, tracking dogs, and officers on horseback as well as aircraft.

Cavalcante apparently slipped through a perimeter.

Authorities describe Cavalcante as extremely dangerous. Police are asking anyone with information to call 911. A $20,000 reward is being offered for information leading to his capture.

In Brazil, prosecutors in Tocantins state say Cavalcante is accused of “double qualified homicide” in the 2017 slaying of Válter Júnior Moreira dos Reis in Figueirópolis, which they allege was over a debt the victim owed him in connection with the repair of a vehicle.