By George P. Hassett
The Ward 5 alderman pulled papers at City Hall Wednesday and entered the race for state representative of the 27th Middlesex district. Sean T. O'Donovan is the third Democrat and fourth candidate overall to declare for the open seat.
The seat was vacated when Patricia D. Jehlen, D-Somerville, became the state Senator for the 2nd Middlesex district.
Elizabeth Moroney, Denise Provost and John A. Roderick are also in the race to replace Jehlen. Moroney and Provost are Democrats, while Roderick is an Independent. The deadline to declare is tomorrow at 5 p.m.