Pretty Little Liars - Biggest Mysteries Finally Answered - best f y

Who killed Ian? (Season 2, Episode 4)
MARLENE KING: Ian killed himself but Mona staged the note and the crime scene.

Who was responsible for killing Garrett and putting Aria in a box with his dead body? (Season 3, Episode 13)
Wilden. Garrett found out that Wilden was a dirty cop and was going to tell. [Wilden] was acting on his own.”