THE EMERG MED SVC (EMS/MEDEVAC) HELICOPTER WAS EN ROUTE WITH A PLT, 2 MED PSNL & A PATIENT. THE PATIENT (A FUGITIVE WITH A GUNSHOT WOUND) WAS HANDCUFFED TO THE STRETCHER. DRG FLT, THE PLT RPRTD A PROBLEM WITH THE PATIENT & REQUESTED POLICE ASSISTANCE DRG ARRIVAL AT THE HOSPITAL. THE PLT THEN TRANSMITTED AN EXPLETIVE & RADAR CONTACT WAS LOST WITH THE ACFT. WRECKAGE WAS FOUND OVER A 1 MI AREA WITH EVIDENCE OF AN IN-FLT BREAKUP & MAIN ROTOR CONTACT WITH THE COCKPIT & TAIL CONE. INV SHOWED EVIDENCE OF SWASHPLATE BRG SEIZURE. THE PITCH CHG LINK RODS & ROTATIONAL SCISSORS WERE BRKN IN THEDRCTN OF MAIN ROTOR ROTATION & CTC MARKS WERE FND ON THE FWD EARS OF THE ROTATING SWASHPLATE LUGS. DISASSEMBLY REVEALED FAILURE OF THE INNER & OUTER RACE LOCKS & SPALLING OF THE BRG RACES. LACK OF GREASE WAS NOTED IN THE BRG & THE BALL BRGSWERE DISCOLORED BLUE. WEAR MARKS ON THE BALL BRGS INDCD SCUFFING; 1 BALL BRG WAS FLUTED. THE BRG ASSEMBLY HAD ACCRUED 1.23 HRS OF OPN SINCE THE LAST 100 HR INSPN. LUBE REQUIRED EACH 400 HRS, COMPANY POLICY WAS TO LUBE AT 100 HR INTERVALS.