The vagrant suspected in the random subway slashings of three women in Manhattan over the weekend was nabbed jumping a turnstile in Harlem on Tuesday and confessed to the knife spree, law-enforcement sources told The Post.

The alleged maniac, 28, is now being grilled by detectives at the NYPD’s Transit District 4 in Lower Manhattan after a two-day manhunt by cops, sources said.

The suspect has four prior busts in the state — including one in the Big Apple — and a history of mental illness, according to sources. It’s un clear what his previous arrests were for.

Police on Monday had released surveillance footage of the suspect jumping the turnstile at the Brooklyn Bridge-City Hall subway station in Manhattan after the third attack.

He is linked to two slashings at the 86th Street and Lexington Avenue No. 4 train station on the Upper East Side around 4:15 p.m. Sunday and another about 20 minutes later at the Brooklyn Bridge-City Hall station, according to police.

The first victim, Bianchelly Diplan, 19, told The Post this week that the creep stared her down, then followed her off the train and slashed the back of her right leg as she climbed the stairs.

“I didn’t know he was behind me on the stairs,” she said. “I felt the cut. It felt like somebody cut me deeply. I looked back at him, and he just stared at me then walked way. I just started crying.”

Diplan said she needed 19 stitches to close the gash.

Police said the suspect cut a second woman at the uptown station before attacking a 28-year-old straphanger at the Brooklyn Bridge station — who sources said was cut so deeply that a tourniquet had to be applied to her leg before she was taken to Bellevue Hospital.