An accused arsonist was released without bail following his arrest for setting fires in a Yeshiva University dorm — only to be sprung again when he was allegedly caught trespassing on Staten Island hours later.

Peter Weyand, 33, was also busted and let go after allegedly menacing a Brooklyn housemate on Dec. 5 — sharpening a knife outside their door while calling out, “Here, piggy, piggy, piggy!” according to police.

Surveillance video shows Weyand kicking through a glass door to Yeshiva’s all-female Schottenstein Residence Hall, after which he used matches meant to light a Hanukkah menorah to set three small fires as students slept at around 3:50 a.m., officials allege.

The blazes, which the FDNY quickly extinguished, damaged a computer, a desk, a pair of commercial toilet-paper rolls and a box of hand sanitizer refills in a closet, court papers say.

Manhattan prosecutors didn’t seek bail for Weyand, 33, at his arraignment on Saturday, saying that the arson and burglary charges against him aren’t “qualifying offenses” under the controversial bail-reform law set to go into effect on Jan. 1.

Instead, authorities agreed to let Weyand go free on “supervised release” by Mayor de Blasio’s Office of Pretrial Services pending another court appearance set for Jan. 23.

“We’re following the new law now, because it would be pointless to make a bail application in a case where the person has to be released a few days from now,” said a rep for Manhattan DA Cyrus Vance Jr.

Weyand walked out of Manhattan Criminal Court at around 7:30 p.m. Saturday, but by 11:30 p.m. he was in custody again, accused of breaking down a fence around a Staten Island backyard and pushing down another fence under the home’s deck.

Weyand was charged with trespassing and criminal mischief, and was released without bail at around noon on Sunday.

House resident Kim Decicco said she and her boyfriend “heard him under the deck.”

“He told us, ‘I was looking for a men’s shelter, I need a place to sleep.’ I suspect he’s been here before,” she said. “I am mad he was released for this, especially after what he did at Yeshiva.”

At the Schottenstein dorm in Kips Bay, senior Rebekah Bargraser, 21, called Weyand “obviously a danger to society.”

“So why, after two crimes, back-to-back, would he be let out on the street again? None of it makes sense. It’s ridiculous,” said the neuroscience student.

In Brooklyn, former housemate Priel Guetta, 29, said Weyand hasn’t been back since he was arrested over a dispute about loud music, in which cops allege Weyand made the “piggy, piggy” remarks at another roommate’s door.

“He’s like The Joker. Something is not normal with him,” Guetta said.

Weyand’s Legal Aid lawyers didn’t return calls for comment.

Additional reporting by Rachel Green