As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON LANDING AS THE NOSE TOUCHED DOWN THE AIRCRAFT STARTED VEERING TO THE LEFT. BOTH REVERSERS WERE NORMAL AND SPEED BRAKE UP. USED DIFFERENTIAL BRAKING BUT WOULD NOT HOLD ON CENTER LINE. USED RIGHT TILLER TO ASSIST BUT IT SUDDENLY JAMMED TO THE LEFT FORCEFULLY. A/C WENT OFF THE RUNWAY THROUGH THE GRASS ONTO A TAXIWAY.