“Drop Dead Diva” (9 p.m., Lifetime): We have a Paula Abdul sighting. The “American

“Drop Dead Diva” (9 p.m., Lifetime): We have a Paula Abdul sighting. The “American Idol” alum shows up in the Season 1 finale of “Drop Dead Diva,” where she plays a judge — of the robe-wearing variety.

“Desperate Housewives” (9 p.m., ABC): Uh-oh. On “Desperate Housewives,” a chance encounter reunites Gaby with John Rowland (Jesse Metcalfe). You know: the lawn boy she used to get busy with.

“Cold Case” (10 p.m., CBS): On “Cold Case,” the 2004 murder of a teen at a juvenile detention center is investigated. The boy was wrongly sent to the facility and was killed before Valens (Danny Pino) could get him released.