The Brooklyn district attorney’s office has ordered a review of some 50 murder cases assigned to an acclaimed homicide detective, an acknowledgment of mounting questions about the officer’s tactics and the legitimacy of the convictions.

The office’s Conviction Integrity Unit will reopen every murder case that resulted in a guilty verdict after being investigated by Detective Louis Scarcella, a flashy officer who handled some of Brooklyn’s most notorious crimes during the crack epidemic of the 1980s and 1990s.

The development comes after The New York Times examined a dozen cases involving Mr. Scarcella and found disturbing patterns, including the detective’s reliance on the same eyewitness, a crack-addicted prostitute, for multiple murder prosecutions and his delivery of confessions from suspects who later said they had told him nothing. At the same time, defense lawyers, inmates and prisoner advocacy organizations have contacted the district attorney’s office to share their own suspicions about Mr. Scarcella.

The review by the office of District Attorney Charles J. Hynes will give special scrutiny to those cases that appear weakest — because they rely on either a single eyewitness or confession, officials said. The staff will re-interview available witnesses, and study any new evidence. If they feel a conviction was unjust, prosecutors could seek for it to be dismissed.