On Monday, he was succeeded by Wendy Ruderman, who was hired away from the Philadelphia Daily News for the post early last month. The self-described “pint-size” investigative reporter won a 2010 Pulitzer for her reporting on a corrupt narcotics unit in the Philadelphia Police Department.

Mr. Baker has moved to the public education beat, Joseph Goldstein will continue representing the Times in the shack, along with Ms. Ruderman.

Times Metro editor Carolyn Ryan told Off the Record that she had been hoping to hire Ms. Ruderman for some time, adding that Metro day assignment editor Dean Chang had previously tried to poach the sixth-borough star to his old paper, the New York Daily News.

“She is a firecracker,” Ms. Ryan said.

Indeed, on her way out of the Philadelphia Daily News, Ms. Ruderman publicly urged her colleagues to join her in leaving the paper, which recently taken over by a group of investors wrangled by former Penn. Gov. Ed Rendell.

“I hate to say it, but if people at the Daily News aren’t looking, they should be,” Ms. Ruderman told the Philadelphia Post. “If they’re not, it’s kind of stupid...This place is rudderless.” (A stern warning, coming from a Ruderman.)

Nonetheless, Ms. Ruderman’s award-winning expose, “Tainted Justice,” co-written with Barbara Laker, resulted in an FBI probe and has been turned into a book, Midnight in the City of Brotherly Love, due next year from HarperCollins.

Asked if the Associated Press’s slew of NYPD scoops (for which they took home a Pulitzer this year) had influenced the shake-up, Ms. Ryan said she was more concerned with the upcoming mayoral election, in which Police Commissioner Ray Kelly is sure to be an influential figure, if not a contender.

Praising Mr. Baker’s “deep institutional understanding” of the NYPD (his father was citywide supervisor in the NYPD Emergency Service Unit), Ms. Ryan said the public schools beat needed his “news-breaking energy.”