Des Plaines resident Justin Cochran is the new state representative for the 55th District, Democratic leaders have announced.

Cochran took the oath of office Dec. 30. He succeeds Democratic state Rep. Marty Moylan, also of Des Plaines, who resigned earlier in December.

In November, on the last day of candidate filing for the March primary, Moylan announced he wouldn’t seek reelection and withdrew. Cochran, Moylan’s chief of staff, submitted petitions the same day and now is the only Democratic candidate for the seat.

It was up to Democratic Party leaders to choose who would finish Moylan’s term, which ends in early January 2027.

The Republican candidate, Glenview’s Joseph Johnson, has criticized the process.