NCIS: In the season finale Gibbs (Mark Harmon) and the team come face to face with the Port-to-Port killer (8 p.m. CBS).
One Tree Hill: Clay and Nathan (Robert Buckley, James Lafferty) search for new clients in the season finale (8 p.m. KTLA).
Dancing With the Stars: The unscripted series offers a "Freestyle Special" (8 p.m. ABC), followed at 9 by the results episode.
Glee: As New Directions works on their set list for Nationals someone at the school deals with the unexpected loss of a loved one in the new episode "Funeral" (8 p.m. Fox).
NCIS: Los Angeles: When Hetty (Linda Hunt) abruptly resigns Callen (Chris O'Donnell) and the team try to figure out why she's gone and track her down in the season finale (9 p.m. CBS).
Hellcats: Marti and Deidre's (Aly and AJ Michalka) discovery that they're kin comes as a surprise to them but probably not to viewers in the season finale (9 p.m. KTLA).
Raising Hope: The Chances reminisce about the year Jimmy (Lucas Neff) turned 18 in the season finale (9 p.m. Fox).
The Voice: Music producer Adam Blackstone and singers Sia Furler, Monica and Reba help the coaches in this new episode of the unscripted singing competition (10 p.m. NBC).
Body of Proof: Megan (Dana Delany) suspects foul play in the death of a young socialite who had a terminal illness. Jill Eikenberry guest stars in this new episode (10 p.m. ABC).
Independent Lens: The new episode "Beetle Queen Conquers Tokyo" looks at Japanese interests in and philosophies about insects (10 p.m. KLCS).
Hockey: NHL playoffs: The Tampa Bay Lightning visit the Boston Bruins (5 p.m. VS).
Baseball: Regional coverage (5 p.m. MLB); the Milwaukee Brewers visit the Dodgers (7 p.m. KCAL); the Angels visit the Oakland Athletics (7 p.m. FSN).
Basketball: NBA playoffs: The Oklahoma City Thunder visit Dallas Mavericks. (6 p.m. ESPN).