It was well after dark yesterday when the man smashed a window, reached inside and unlocked the door, Prince George's County police said. The woman upstairs heard him, shut herself and her child in a bedroom and dialed 911.

Within two minutes, the sound of a siren filled the air, police said, apparently prompting the intruder to flee the house in the 2700 block of Iverson Street, in the Hillcrest Heights area.

Police said they confronted him behind the house. He fired, an officer fired, and the suspect was hit at least once and critically wounded, a police spokesman said.

"I just want to applaud the officer for his quick response," county Police Chief Melvin C. High, who went to the scene in black tie, said on WTTG-TV (Channel 5). "I'm always worried when an individual breaks into an occupied house."

The suspect, who was not immediately identified, was taken to Washington Hospital Center.

Details about the confrontation, which occurred about two blocks west of Iverson Mall, were not immediately available. However, Capt. Andy Ellis, a police spokesman, said the suspect fired at least once.

Police said they took custody of a shotgun afterward.

According to police, the evening break-in may have followed as many as two others in the same neighborhood yesterday. One resident, speaking on television, said he returned home yesterday to find his house ransacked.

Police were nearby when the woman called 911 yesterday evening, police said.

Neighbors said they heard several gunshots, fired in what sounded like a single, rapid volley. "Four shots," one resident said. "All at once."

They said they saw a man placed in an ambulance and driven away. No injury to officers was reported.