A federal judge yesterday sentenced John J. O'Grady, the Fairfax County man accused of kidnaping the daughter of a Northern Virginia banker last September, to 15 years in prison on an extortion count related to the $50,000 ransom paid for the woman's release.

"I'm sorry for what I've done and for the pain it's caused my family and loved ones," O'Grady, 33, told U.S. District Court Judge Albert V. Byran Jr. in Alexandria moments before Bryan imposed the sentence.

O'Grady, who has described himself as unemployed and heavily in debt at the time he allegedly abducted his victim, Carol Lynn Drewer, faced a maximum of 20 years in prison and a $10,000 fine on the extortion charge. He pleaded guilty last Nov. 26 and federal prosecutors dropped three lesser charges in exchange.

O'Grady's attorney, Christopher Hopkins, yesterday asked Bryan for further psychiatric tests to determine the "why's and wherefore's" of his client's actions, which Hopkins said were out of character for O'Grady. Bryan denied the request.

The only-haired O'Grady still faces kidnapping and related charges in Alexandria and Arlington in connection with two alleged attempts to abduct Drewer. The 19-year-old woman was seized at gunpoint at 8 a.m. on Sept. 23 outside the First American Bank headquarters at Tysons Corner.She was released 14 hours later after her father, bank chain president Milton Lee Drewer, left $50,000 in small bills at another location.