A shoplifting suspect and a security guard were wounded last night in an exchange of gunfire in a parking lot at Landover Mall, Prince George's County police said.

The suspect was in critical condition and the security guard was in satisfactory condition last night after surgery at Prince George's General Hospital, police said.

The injured men's names were not immediately available.

Mall security guards were notified about 4:45 p.m. by employes of the Woodward & Lothrop store in the mall that a man suspected of shoplifting was leaving the store, said Cpl. Bruce Gentile, a police spokesman.

Two security guards employed by the mall followed the man out of the mall to the parking lot, Gentile said, where the man got inside an automobile and turned on the ignition.

The guards ordered the man out of the car, Gentile said, and when he left the car, he began scuffling with one of them.

The man ended up holding the guard's handgun, Gentile said, which he used to shoot the guard once in the thigh.

The man started to run from the scene, Gentile said, but stopped and fired at least one shot at the second security guard.

The second guard then fired at the man, wounding him, police said.

The mall, bounded by Landover and Brightseat roads and the Capital Beltway, is a popular hangout for teen-agers and young adults.

"I wouldn't say it was the worst shopping center in county" as far as crime problems are concerned, Gentile said. "We have our fair share of problems here. There were some problems here in the past with security guards."

Two former security guards were found guilty in August of assaulting two shoppers during an arrest in November 1984.

One of the shoppers later pleaded guilty to trespassing and the other, a teen-ager, was found in a juvenile proceeding to be "involved" in trespassing.

Since that incident, said Stanley Jaffe, manager of the mall, a new head of security has been hired and new hiring procedures have been instituted.

Both Jaffe and police said yesterday was the first time a Landover Mall security guard had fired his gun.

"This unfortunate incident could have occurred at any shopping center," Jaffe said.