The man tried to escape through the doors to the next car, but they were locked and the train started to pull away from the station, McCullough said.
Now, McCullough was locked inside the car, alone with the other man. But the man had run out of steam, McCullough said. The man sat at one end of the car, pulled out a vodka bottle and took a drink.
McCullough said he shouted at him, "You are f***ed."
When the guy stood up and brandished the knife, McCullough said, he told him, "Sit, the f*** back down."
McCullough said the train stopped before leaving the station, and a conductor came and ushered him out, leaving the other man. About 10 police officers then jumped on the train and handcuffed the guy, McCullough said.
At the 33rd Precinct, McCullough said he learned that his assailant, identified as James Torres, 39, 6'3" and 240 pounds, had a long arrest record and once allegedly had stabbed two officers.
When one of the officers recognized McCullough from his role on "CSI," he was asked to sign autographs and take pictures.
"It's just a very surreal experience, going from almost getting stabbed to being asked to take pictures and sign autographs," he said. "I'm very thankful it all resolved the way it did."