Investigators yesterday arrested a 23-year veteran of the New York City public schools, Joan Mahon-Powell, on felony charges of using a false state-issued school administrator’s license.

Ms. Mahon-Powell, 48, who was forced out of her job as one of the city’s 113 local instructional superintendents last fall after the Department of Education first questioned her license, rose through the ranks of the city’s public school system without ever achieving so much as a certification to teach, the city charges.

She is facing criminal possession of a forged instrument in the second degree and offering a false instrument for filing in the first degree, which could net her up to seven years in jail.

“It was a real ‘Catch Me If You Can,'” the special commissioner of investigation for New York City schools, Richard Condon, said, referring to the 2002 Leonardo DiCaprio movie about a successful con artist.

Ms. Mahon-Powell got her first New York City teaching job in 1981. She was demoted seven years later after she had failed to achieve her teaching certification. Then, after acting as a substitute teacher for four years, the woman who hadn’t achieved a teaching certificate was appointed as an assistant principal – a job that requires a school supervisor’s certificate.

At the time, education officials saw nothing amiss about the supervisor’s certificate she presented, but in a letter yesterday to Schools Chancellor Joel Klein, Mr. Condon wrote that the document was not “genuine.”

With that credential on file, Ms. Mahon-Powell was promoted in 1997 to become a full-fledged principal. In 1999, she was promoted to the interim acting superintendent of Brooklyn’s District 19.A year later, she was promoted again, to superintendent of the Chancellor’s District. In 2001, she became the liaison to the City University of New York.

In July 2003, Ms. Mahon-Powell achieved her final promotion, becoming the local instructional superintendent of Region 6.That position put her in charge of around 10,000 students in a network of about a dozen schools in Brooklyn. Only then – after more than two decades of employment – did education officials notice there was something wrong with Ms. Mahon-Powell’s certificate.

According to Mr. Condon, the education department contacted the state education department, which couldn’t find any administrator certificate on file for Ms. Mahon-Powell. The state recommended that the city inspect Ms. Mahon-Powell’s original certificate.

At first, Ms. Mahon-Powell tried to avoid meeting with her supervisors. When she finally showed up, she brought a suspicious-looking certificate encased in plastic that had a different date and number than the ones in her file, Mr. Condon said.

She claimed the original had been damaged and that she was showing a replacement issued by the state.

Mr. Condon charges that Ms. Mahon-Powell tricked a subordinate, Joan King, into handing over her certificate, which Ms. Mahon-Powel altered and presented to authorities as her own.

Mr. Condon said “everyone was surprised” when his office uncovered the alleged deception. “She had been in the system for 20 years,” he said.

The general counsel for the schools chancellor, Michael Best, said in a statement that when education officials discovered the apparent fraud last year; they “immediately notified” Mr. Condon’s office and fired Ms. Mahon-Powell.

“She has been placed on the ineligible list and will never work for the department again,” he said. “Improved background procedures are now in place to ensure that such a fraud will not occur again.”