A U.S. Park Police officer shot and wounded a man who approached him with a hunting knife yesterday after the officer went to the aid of another man who said he was being attacked, Park Police said.

Earl D. Edwards, 40, who told police he is from Des Plaines, Ill., and who is apparently homeless, was hit in the right side by a gunshot. He was listed in good condition at George Washington University Hospital, police said, and he was charged with assault and assault on a police officer.

Officials said that Edwards was shot by Officer Relis Woods, 36, who has been on the force for eight years. Maj. Richard J. Cusick, a Park Police spokesman, said it was unlikely that Woods would be placed on administrative leave.

Woods, patrolling the area near the White House on a motor scooter, was flagged down about 7 a.m. by a man in the 1700 block of Pennsylvania Avenue NW who said a man was threatening him with a knife, police said.

Woods radioed for backup, then approached the other man, who pulled a knife and threatened the officer, according to police. The man kept coming toward the officer, who ordered him to drop the knife, police said. When the man refused, Woods shot him, according to police.

Police were unable to identify the man who originally flagged down Woods.