The homeless man who allegedly shoved an off-duty NYPD cop onto Manhattan subway tracks late Tuesday is a career criminal who was recently cut loose on supervision after randomly slugging someone else on the rails, cops and prosecutors said.
Aaron Walker, 28 – who has 18 prior arrests – had only been out of cuffs for two days when cops say he hurled the 24-year-old officer onto the downtown roadbed at the Third Avenue L station in the East Village shortly before 7:30 p.m., sending him to the hospital.
Walker was picked up by police a short time later and now faces a top charge of attempted murder, authorities said…