In a predawn encounter inside the Arlington Cemetery subway station yesterday, Metro security police shot and wounded a 25-year-old Washington man suspected with four others of attempting to burglarize the farecard machinery.

It was the first time a Metro police officer has used his gun in the line of duty since the system began operations four years ago, a Metro spokesman said.

The wounded suspect, John Alsbrook, was listed in fair condition at Arlington Hospital yesterday after removal of two .38-caliber slugs from his right bicep and lower right abdomen.

Alsbrook had not been arraigned and was guarded by Metro police standing outside his hospital room. Four other suspected accomplices were being held by Arlington police in lieu of $50,000 bail. They have been charged with attempted murder, possession of burglar's tools, attempting to open Metro machinery, attempted grand larceny and use of firearms.

The Metro spokesman said Alsbrook previously was convicted of burglarizing the Deanwood station, near his home in Northeast Washington. Yesterday's was the 60th break-in of a Metro subway station.

According to police accounts, officers John Grazioso and William Dunn were on a routine patrol of Metro stations Thursday night. At approximately 4:50 a.m. yesterday morning, as they approached the Arlington Cemetery station from an access road, Grazioso spotted a car that he recognized as one used in a prior burglary.

Grazioso and Dunn approached the car on foot and found inside a man, a woman and an infant child. The woman, 26-year-old Barbara Ann Little, is the wife of another suspect in the case, the Metro spokesman said. The man is 28-year-old Warren D. Scarbro.

While Grazioso kept the suspects under guard at the car, Dunn descended through the darkness in the station's elevator with his hand on his gun. In the station, partially illuminated by night lights, Dunn stepped out of the elevator and found Alsbrook, 28-year-old Moses Steel and 27-year-old Harvey Little crouched together nearby.

They had breached the station's accordion security gate. One of them, the spokesman said, held a crowbar.

Dunn immediately ordered the trio to "freeze," the spokesman said. But, Alsbrook, he said, drew a .25-caliber automatic pistol.

Dunn quickly fired two shots with his .38 revolver, hitting Alsbrook in the arm and abdomen. Dunn held the trio under arrest until Arlington police arrived.

Alsbrook was taken to Arlington Hospital for surgery.

The Metro spokesman said the Arlington Cemetery station, seldom used after dark, has been burglarized "several times" before.