The Upper West Side resident arrested for slashing a Danish tourist after his mother identified him to cops has also been charged with threatening a former co-worker, the Daily News has learned. Joshua Zinberg, 25, was charged with harassment and aggravated harassment after sending threatening text messages to his 32-year-old co-worker in April 2023, cops said. The texts caused the co-worker to “be placed in fear of his safety,” police said. The content of the text messages was not immediately disclosed. The threatening texts came to light Friday while Zinberg was arraigned for attacking a 55-year-old tourist from Denmark on W. 86th St. near Columbus Ave. at about 10:20 a.m. Wednesday, cops said. The tourist is a former professional soccer player, ABC7 Eyewitness News says. Obtained by Daily NewsJoshua Zinberg is pictured in surveillance video on Wednesday. (Obtained by Daily News) Cops recovered surveillance footage of the slasher wearing a T-shirt and shorts. After they released the footage to the media, Zinberg’s mother came forward, telling police they were looking for her son, sources said. Zinberg lives with his parents in an apartment building just around the corner from where the attack took place. He’s charged with attempted murder, assault and weapon possession. Zinberg spat at news reporters and photographers when he was led out of the 20th Precinct stationhouse in handcuffs Thursday afternoon to appear in Manhattan Criminal Court. “That’s for all of you,” he said to the gathered journalists. “Do it for the clicks!” “You guys don’t know s–t,” he said after a reporter shouted a question about his mother turning him in. Barry Williams / New York Daily NewsJoshua Zinberg spits at reporters outside the 20th Precinct station house on Thursday. (Barry Williams / New York Daily News) According to police, Zinberg allegedly came up behind the tourist — who was walking with two companions — and slashed him from the right ear, along the right cheek and down to his neck. “F— you, guys!” he reportedly shouted at the trio before running off. The victim’s friends and the super of a nearby building aided him, giving him a shirt, towel, and a rag to apply to his wound before a nurse who lives in a nearby building gave the victim an ice pack. The man was taken by medics to Mount Sinai Morningside in stable condition. Police said the attack was unprovoked. It was not immediately clear what set Zinberg off. The bloody assault comes on the heels of a horrific random triple murder that played out on Manhattan’s streets earlier in the week. On Monday, three people were stabbed to death in the string of unprovoked knife attacks, which spanned from Chelsea to Kips Bay to near the United Nations. Ramon Rivera, 51, has been charged with murder in each of those three attacks.