Henry Ian Cusick
Credit: Michael Tran/FilmMagic

Henry Ian Cusick – who starred on Lost and Scandal — will stay in the ABC family by guest-starring on Body of Proof.

EW has learned exclusively that Cusick will play a psychologist named Trent Marsh who has patients that Megan (Dana Delany) and Tommy (Mark Valley) are carefully watching while investigating a murder case.

Body of Proof is set to return to ABC’s lineup in early 2013.

Cusick played Stephen Finch in the first season of Scandal but is best known to audiences as Desmond Hume from Lost. In season four of Fringe, he debuted as Simon in the flash forward episode “Letters in Transit.” The Fringe showrunner has teased that Cusick may return for the drama’s last season on Fox.