Ann Cleary (Gretchen Egolf) is a villainess from "Cellar Boy," the penultimate episode of Blue Bloods' first season (airdate May 6, 2011). She is the sister of Al and Ronnie Cleary.
Both Ann and Al arrived at their home, where their parents were brutally murdered, after which Al voiced his suspicions that the murders were committed by their younger brother Ronnie Cleary. Regarding Ronnie, he was revealed to have had a history of drug use, and that and the abuse he suffered at home (among other things, his father called him "Cellar Boy" after Ronnie moved into the basement), made him the primary suspect. Though Ronnie was interrogated by Danny Reagan and offered legal counsel by Erin Reagan (the Reagans and Clearys having known each other for years), Danny's suspicion later turned to Al and Ann.
Ann was visited by Danny and Erin, which saw Ann voice her jealousy of the Reagans by referring to them as "perfect" and bringing up Erin's divorce being the subject of gossip. Danny--who pointed out that Ann was packing her things in a hurry--stated to Ann that the murder weapon (a kitchen knife) was found and that it would be difficult to test for prints due to the killer most likely wearing gloves. In actuality, this was part of a ruse due to his suspicion of Ann and Al as the killers, and during Danny's stakeout of the car dealership with Jackie Curatola, the trap works, and the siblings are seen arguing before they went to an area where Al took out the blood-covered knife, cementing their reveal.
As Erin revealed to Ronnie, Ann confessed to the murders, which were motivated by money. The siblings were upset over their parents spending money they believed was theirs to inherit, even though it was spent on Ronnie's rehab. After learning that their parents planned to go on a big trip, Ann turned heel and colluded with Al on his plan to kill their parents to gain their inheritance, with the sinister siblings stabbing their parents to death the night before the episode's events. In addition, they planned to frame Ronnie for the murders, and as part of the scheme, the evil Ann drugged Ronnie's grapefruit juice with sleeping pills, while Al wore Ronnie's shoes at the scene, after which they were set to plant the knife in Ronnie's hotel room. The siblings were arrested (off-screen) following their reveal.
- Gretchen Egolf later played villainess Helen Barnes on Reckless.