POCOPSON TWP., Pennsylvania -- The mother of an escaped killer on the loose in Chester County, Pennsylvania is now helping authorities in the search for her son, as officials said they believe they are closing in on the "dangerous fugitive" after four credible sightings were reported over the Labor Day weekend, including one by a state trooper.
Danelo Cavalcante remained at large Monday afternoon and police suspect he is hiding out in a residential neighborhood in Pocopson Township, Pennsylvania, near the prison he escaped from on last week, officials said.
Lt. Col. George Bevins, deputy commissioner of operations for the Pennsylvania State Police, said at a news conference Monday afternoon that 34-year-old Cavalcante was spotted Sunday afternoon from a distance by a state trooper, who gave chase but lost him. Bevins said it was the fourth credible sighting of Cavalcante in Pocopson Township since his escape from the Chester County Prison.
Bevins said the trooper spotted Cavalcante in the same general area where the fugitive was recorded on a Ring doorbell camera early Saturday lurking in a residential neighborhood about 1.5 miles from the Chester County Prison.
"He is desperate. He does not want to be caught. He has very little to lose at this time," Bevins said of Cavalcante, who officials said is also wanted in his native Brazil on homicide charges.
He said search efforts are intensifying with more resources being deployed in hopes of pressuring Cavalcante to the point he gives up or makes a mistake.
"I intend to stress him. I want to push him hard. He'll make mistakes. He'll show himself. He's already shown himself, we believe, a few times," Bevins said.
Bevins said investigators got Cavalcante's mother to record a message asking her son to surrender peacefully. He said the message was being broadcast from police helicopters and vehicles in the search area.
He said the message from Cavalcante's mother, who is from Brazil, is recorded in her native language of Portuguese.
Cavalcante's escape came about a week after he was sentenced to life in prison without the possibility of parole for murdering his ex-girlfriend, 38-year-old Deborah Brandao, who prosecutors said was stabbed 38 times in front of her two young children, ages 4 and 7, at a home in Schuylkill Township. A Chester County jury convicted Cavalcante after just 15 minutes of deliberations.
Prosecutors said Brandao was killed after she learned Cavalcante was wanted for murder in Brazil and threatened to expose him to police.
Following Brandao's murder, Cavalcante fled to Virginia, where he was arrested and brought back to Pennsylvania to face justice for Brandao's killing.
Cavalcante escaped from the Chester County Prison on Thursday. He was discovered missing from the prison around 8:50 a.m. He was being held there pending transfer to a state correctional institution.
The escape remains under investigation by the Chester County District Attorney's Office and the state police.
Citing the ongoing investigation, Chester County District Attorney Deb Ryan declined to provide details Monday on the circumstances of the breakout.
"The prison is very aware of the vulnerabilities that they have and they have made efforts to correct those vulnerabilities," Ryan said.
Pennsylvania Gov. Governor Josh Shapiro issued a statement on social media Monday advising residents of Pocopson Township to remain vigilant, keep their doors and windows locked and report anything suspicious to authorities immediately.
Bevins said police have investigated two home burglaries reported in the area since the escape, adding, "I can't confirm it was him, but they are of interest to us."
Ryan said authorities plan to brief local school superintendents Monday afternoon on the search. She said it will be up to the school superintendents to decide whether to cancel classes on Tuesday.
It was the second time in less than two months that a dangerous inmate had escaped from a Pennsylvania prison. Inmate Michael Burham, who is a suspect in the rape and murder of a 34-year-old woman in Jamestown, New York, escaped from the Warren County Jail in northern Pennsylvania on July 6.
Burham, an Army reserve sergeant who authorities said was a "self-taught survivalist," was captured on July 15 following a massive manhunt in the northern Pennsylvania woods.
ABC News' Ahmad Hemingway, Meredith Deliso and Nadine El-Bawab contributed to this report.