Timothy J. Dowd, the New York City police detective who led the manhunt that finally ensnared David Berkowitz, the serial killer who called himself the Son of Sam and whose yearlong shooting spree and evasion of the police spread fear across the five boroughs, died on Friday in Millbrook, N.Y. He was 99.

His daughter, Melissa Dowd Begg, confirmed his death.

The Son of Sam killings, which occurred at a time of fiscal crisis and high crime in New York City, became an emblem of a city in desperate straits.

Beginning on July 29, 1976, when he shot and killed Donna Lauria, an 18-year-old Bronx woman, and wounded her friend, Jody Valenti, 19, Mr. Berkowitz murdered six people and wounded seven others in attacks in the Bronx, Queens and Brooklyn before he was captured on Aug. 10, 1977. He was also known as the .44-caliber killer, for the weapon he used.

The shootings seemed random but for a small number of similarities: They occurred at night, and six of the eight separate attacks involved couples sitting in parked cars; several of the victims, including one man, had long, dark hair. The killer taunted the police with letters, one left at the site of the sixth attack, in the Baychester section of the Bronx, where Valentina Suriani, 18, and Alexander Esau, 20, were killed on April 17, 1977. Another was sent to the Daily News columnist Jimmy Breslin, in early June. Tension in the city was so high that Mayor Abraham D. Beame instructed the police to chase couples from known lovers’ lanes.