A police cadet who had just written a ticket for an illegally parked car was able to give police officers information that led to the arrest yesterday of four suspected bank robbers who, police said, used the ticketed vehicle as a getaway car.

Cadet Timothy White, 20, said he had just filled out the ticket (for illegal parking in a Metro construction area) when four men brushed by him, grabbedthe ticket from his hand, jumped into the car and sped off.

Moments earlier, a Riggs National Bank branch at 318 7th St. NW had been robbed by three armed men while a fourth stood guard. All four wore ski masks, according to Capt. John Conner, of the robbery division.

Shortly after the robbery, White had his encounter with four men a block away at 8th and D Streets. The unarmed cadet had no reason to suspect the quartet at the time, but noted the license tag numbers of the vehicle anyway. Moments later, he heard a broadcast desribing the robbery and realized that the ticketed quartet matched descriptions of the wanted men.

He alerted officers to the tag numbers and thecar they sought was stopped on Martin Luther King Avenue shortly afterward.

Charged with armed robbery, according to police, were Glen Smith, 24, of 45 R St. NW; Anthony Brown, 20, of 1113 D St. SE; Husher Bussey Jr., 21, of 1521 D St. SE; and a 17-year-old juvenile.