More details have emerged on the gruesome stabbing on the D train yesterday that left one straphanger dead and another behind bars. Bronx resident Geraldo Sanchez, 37, allegedly stabbed Dwight Johnson, 36, repeatedly in the face and neck in an altercation that started when the victim declined to move his bag from a seat on the crowded train.

Sanchez boarded the first car of the northbound train at Rockefeller Center just before 2 am and demanded that Johnson move his bag from an unoccupied seat, "saying he had just gotten off work and was tired," according to the Post. Johnson — who appeared to be homeless and stood at least six inches taller than the suspect — declined, and the pair started swearing at each other. Then Johnson punched Sanchez in the face, and Sanchez pulled out a steak knife. "He stabs him right in the neck, possibly the jugular," a police source told the Daily News. "Blood everywhere. Complete mayhem."

Some of the two dozen other passengers in the car banged on the conductor's door and pulled on the emergency cord, bringing the train to a "screeching halt" in the tunnel before the Seventh Avenue and 53rd Street station. According to the Daily News, straphangers scrambled away from the attack and used the intercom to notify train crew. When the train arrived at the station, the conductor kept the car's doors locked and alerted MTA workers, who in turn called police. During the five minutes before police arrived, Sanchez managed to pry open the train doors "just enough to drop the knife out of the train," according to the Post, though cops later recovered the weapon.

When police boarded the train, where according to the Daily News "pools of blood were left along the length of the car," the suspect tried to blend in with the other commuters stating: "'What? I didn't do nothing,' like nothing happened, like he's just another passenger," a police source said. When officers cuffed him and escorted him off the train, the Post reports that Sanchez told cops: "He punched me in the mouth." The suspect — who at the time of the crime was wearing a polo shirt emblazoned with the name "Jerry" and the words "Terminate Control" — works as an exterminator and had been acting strangely and abusing pain killers since he fell two stories and injured himself at work two weeks ago, according to friends and neighbors. "He was in pain because he fell," said his brother Louis Sanchez. "He was talking about headaches and backaches, and he was taking some kind of medication." On the day of the crime, the suspect had been sent home from work by his boss for showing up late, according to co-workers at Terminate Control. "But he took it in stride," one co-worker said. "Jerry's not someone to hold a grudge."