Lured back to the city he left four and a half years ago, Oak Bluffs police chief Joseph C. Carter yesterday submitted his resignation to selectmen and announced he is headed to Boston next month to take over as chief of the Massachusetts Bay Transportation Authority (MBTA) police department.

A selection committee from the MBTA board unanimously picked Chief Carter yesterday to head up the MBTA police force, a department embroiled in controversy during the last year over issues of racial profiling.

The chief's resignation in Oak Bluffs will take effect on Jan. 13, according to selectmen chairman Todd Rebello.

Mr. Carter, 46, hopped off the fast track in June of 1998 to come to Oak Bluffs. A former superintendent in the Boston police department, Mr. Carter was not only the highest-ranking black officer but also the youngest person ever promoted to its command staff. The salary he accepted in Oak Bluffs was almost half what he was making in Boston.

Chief Carter told the Gazette yesterday that members of Governor-elect Mitt Romney's transition team tapped him just days before the November election, saying they were eyeing him for the MBTA job.

"I feel I've done what I can do here," Chief Carter told the Gazette in a telephone interview last night. "Oak Bluffs has been an exciting journey and a rewarding one professionally. The department is transformed to a professional, mission-oriented police agency and I believe a model for agencies of its size."

While Chief Carter said his decision to come to the Island four years ago was rooted in a desire to spend more time with his wife and daughter and to find a less stressful pace, his ambitious streak was ever present. While running the Oak Bluffs police department, Mr. Carter was also appointed commander of Army National Guard Training at Camp Edwards in Otis and elected vice-president of the International Association of Chiefs of Police.

And clearly, Mr. Carter is drawn to the challenge of turning around a police force which has been at the center of a political storm for much of the last year, the subject of at least two reviews charging the department with unfairly targeting minorities for police action.

Town leaders had known for the last month that their police chief was shortlisted for the MBTA post. "The chief kept us informed, and we weren't very surprised … that he would not have finished his career here," said Mr. Rebello. "Someone of his caliber needs to be challenging himself every day, and he's going to find that."

Selectmen will begin a search process for a replacement as soon as possible. Mr. Rebello said his board would not rule out the possibility of an in-house candidate for the post of chief.

Just what selectmen are looking for remains to be seen. "The issues that face Oak Bluffs today are not necessarily the issues that faced Oak Bluffs five years ago," said Mr. Rebello.

It's widely acknowledged that when Oak Bluffs recruited Joe Carter back in 1998, they badly needed a strong chief who could rescue an ailing police force.

"The department was in a state of disorganization. There was low morale," said selectman Richard Combra. "There was confusion within the department and the need for leadership."

Chief Carter is credited with retooling the department, hiring new officers, winning grant funding and beefing up narcotics enforcement.

"His finest accomplishment was raising the level of professionalism," said Mr. Combra. "Joe embraced the community policing model … and recruited and assembled a police force as professional as any in the commonwealth."

Chief Carter himself said the Oak Bluffs department was in a sorry state when he came on the scene. "It was a department that was broken and needed major overhauling," he said.

In his tenure, Chief Carter added three more full-time police officers, bringing the full-time roster to 13. But perhaps his most significant accomplishment was helping to defuse racial tensions that had begun to build around the Fourth of July celebrations.

Working closely with Edgartown police chief Paul Condlin, Chief Carter pulled in the reins on the mounted police presence and called in youth workers from Boston along with members of Boston police gang-units to roam the streets and interact with the crowds.

Together, the two chiefs successfully sent a message that the Island welcomed visitors but would not tolerate loud, all-night partying. Within just two years, they had turned an explosive situation into something manageable.

But amidst all the plaudits and achievements of Chief Carter's four years in Oak Bluffs, his time was not without controversy and disappointment. Last year, the chief came under fire from the town finance committee after selectmen quietly handed Mr. Carter a check totaling more than $67,000 in overtime pay, nearly equal to his $70,000 annual salary.

The finance committee questioned whether the chief's contract allowed for the overtime payments and promised a fuller investigation into the matter. But the issue failed to gain much traction, and the chief stopped logging overtime hours at the same rate.

For Chief Carter, the one goal left unmet would have to be the police station, which still sits in the same cramped building downtown. "My only complaint is that I was unable to garner enough energy behind a new police building," he said.

As Chief Carter prepares to head up a police force of 235 officers at the MBTA, he said his home will remain in Oak Bluffs, and his wife will continue teaching at the Oak Bluffs School.

Still, it's obvious that Mr. Carter can hardly wait to sink his teeth into the next challenge. "The MBTA is in dire need of strong leadership," he said. "It needs someone who can re-engineer a department that's lost a lot of public confidence."