NEW YORK (AP) _ New York City police are among the more restrained in the nation in using their guns, experts say, contrary to a common perception reinforced by this week's killings of an unarmed woman and a veteran police officer.

''Many people say ... 'They're killing people left and right,' but that's directly counter to the figures,'' said Thomas Reppetto, a former Chicago police commander who is president of the Citizens Crime Commission of New York City, a watchdog group.

Tighter guidelines for the use of deadly force began developing after a federal study found that police shootings helped spark 13 riots in the 1960s, said James Fyfe, a former New York policeman who is chairman of American University's Department of Justice, Law and Society.

''New York was really at the forefront in terms of the degree of the restrictiveness of the policy, and remains the most restrained among the large police departments in terms of shooting,'' Fyfe said.

None of which consoles Guy Ferraro, whose 31-year-old wife, Lidia, was killed early Wednesday in a hail of police bullets after a car chase that began when she ran a red light.

''She was defenseless. They surrounded her. It was coldblooded murder,'' said Ferraro.

Police said afterward that a sergeant had fired three shots at the car's tires. Because of a police radio report that shots were fired, officers who converged on the scene may have thought the woman fired the shots and was armed, police said. No weapon was found in her car.

The same day, a veteran officer was shot during a drug raid. The fatal bullet came from another officer's gun - not the gun of a woman arrested in the raid, as police originally reported.

Asked if firearms policy would be changed in the aftermath of the two shootings, Chief of Detectives Robert Colangelo responded, ''We are constantly reviewing our policy.''

The sergeant who shot out Mrs. Ferraro's tires apparently violated a 1985 department regulation against firing shots at a moving vehicle. The sergeant was suspended.

Virtually all major police departments have similar rules, experts said. A 1986 U.S. Supreme Court ruling said deadly physical force may not be used to stop a fleeing felon.

Fyfe, who researched police shootings in New York for his doctoral thesis, found that a restrictive policy instituted in 1972 led to a sharp drop in the number of fatal police shootings, which reached 87 in 1971.

From 1981 through 1984, the average was 33; in the past three years, it was 15, according to police figures.

The International Association of Chiefs of Police studied police shootings in the 57 largest cities from 1975 through 1983. Fyfe said that in terms of the number of fatal shootings per 1,000 officers, New York had a relatively low rate of 1.36.

The highest rates were Jacksonville, Fla., at 7.17, followed by New Orleans at 6.8 and Long Beach, Calif., at 6.1. At the lower end of the scale were Boston, 1.19; San Francisco, 1.4; Minneapolis, 1.62; and Chicago, 1.71.

In other major cities, the rate in Dallas was 4.32; Houston, 4.73; Los Angeles, 3.05; Detroit, 3.33; and Atlanta, 3.28.

Robert Trojanowicz, director of the School of Criminal Justice at Michigan State University, said that in the past 15 to 20 years, fatal shootings by police have declined ''because they're getting extensive training, and policies are becoming increasingly refined, specific and restrictive.''

''In the past,'' he said, ''a person was given a weapon, put on the street and expected to literally learn on the job.''

Internal investigations and pressure from citizens make it ''very difficult with current procedures to cover up an errant police officer's actions,'' Trojanowicz said.