In a significant law enforcement breakthrough with likely national implications, the New York Police Department has adopted a broad policy of videotaping custodial interrogations in murder, serious sex crime and felony assault cases.

Commissioner Raymond Kelly announced the initiative last week. Aimed at deterring false confessions, and strengthening police and prosecutorial credibility and integrity, the plan will use private money from the Police Foundation to help install video capability in every police precinct and make videotaped interrogations standard procedure. It builds on a two-year pilot program in Brooklyn and the Bronx, as well as recommendations from the Innocence Project and a task force created by the state’s chief judge, Jonathan Lippman.

False confessions figure in about a quarter of the cases where convicted individuals are later exonerated based on DNA evidence. Recording suspects’ statements in custody on tape, Mr. Kelly correctly noted, “can aid not only the innocent, the defense and the prosecution but also enhance public confidence in the criminal justice system by increasing transparency as to what was said and done.” About 20 states and the District of Columbia currently, by law or court order, require that interrogations for certain crimes be recorded, according to the New York State Bar Association. Given New York City’s size and status as a crime-fighting leader, its embrace of taped interrogations is bound to be influential.

Earlier this year, the New York State Legislature unwisely rejected legislation backed by Mr. Lippman to require videotaping of interrogations in serious cases across the state. Mr. Kelly’s move, laudable though it is, is no substitute for enacting uniform and enforceable statewide standards mandating videotaped interrogations and also fixing skewed lineup procedures, another major cause of wrongful convictions.