A man charged in a pair of New York City subway stabbings last year has been found dead in his cell on Rikers Island. Donny Ubiera, 33, was in a mental observation cell before winding up unresponsive Tuesday, authorities said. Ubiera allegedly went on a violent spree last June, striking a bakery worker with a board and then stabbing two people on a Queens subway—in seemingly unprovoked attacks—all in the span of a few days. He’s the eighth person to die in 2023 after being held on Rikers Island, but his cause of death is unclear.