From 2003 to 2011, O'Brien was a member of the Connecticut House of Representatives and represented the 24th Assembly District, which includes parts of New Britain and Newington, Connecticut. From 1997 to 2003, O'Brien was a member of the New Britain City Council.
From 2003 to 2011, O'Brien served in the Connecticut House of Representatives representing the 24th Assembly District, which encompasses parts of New Britain and Newington, Connecticut. From 1997 to 2003, O'Brien was a member of the New Britain City Council.