Two-thirds of the members of the Board of Aldermen want Mayor John DeStefano Jr. to hold off on hiring assistant police chiefs.

While the New Haven Police Department has only one assistant chief, down from four, a letter signed by 20 aldermen asks DeStefano to consult the Board of Aldermen before filling the three vacancies.

“We believe the current vacancies present a unique opportunity to take a look at the department, its supervisory needs, and its organizational structure,” the aldermen wrote. Despite Chief Frank Limon’s request for two new assistant chiefs at a Mar. 2 Board of Aldermen meeting, alderman said new chiefs should not be hired “simply because the positions happen to be budgeted and vacant.”

The letter follows a recent effort by Ward 17 Alderman Alphonse Paolillo Jr. and Ward 12 Alderman Gerald Antunes, a retired New Haven police officer, to pressure DeStefano to hire back the 16 officers the city laid off in February before hiring new assistant chiefs.

Assistant Chief Thomas Wheeler announced Mar. 8 he would be leaving the department to “pursue a career in academia,” according to a city press release. Assistant Chief Ariel Melendez, who ordered the SWAT raid at the Morse-Stiles Screw at Elevate in October, retired in January.

Only Tobin Hensgen, recruited from Chicago along with Wheeler, remains on as assistant chief.