"The Killing": Rosie Larsen's murderer didn't see it coming

(CBS News) After two seasons, loyal viewers of AMC's "The Killing" finally found out who killed Rosie Larsen, but - true to the show's slow burn pace - it wasn't revealed until the final minutes of the episode's end. (SPOILER ALERT)

Read More: "The Killing": Jamie Anne Allman talks "shocking" season 2

Throughout the show's course viewers were misguided with one red herring after another, but in Sunday night's season finale it was revealed that the real culprit behind Rosie's murder was her aunt Terry Marek (Jamie Anne Allman) who tearfully confessed to driving Rosie into the lake.

At the beginning of the episode it appeared that Darren Richmond's campaign manager, Jamie Wright (Eric Ladin), was guilty of killing Rosie after a flashback revealed he discovered that she overheard him conspiring with Wapi Eagle Casino manager Nicole Jackson (Claurdia Ferri) and property developer Michael Ames (Barclay Hope) to help Richmond win the election.

Jamie confronted Rosie after he discovered she had witnessed the event and hit her over the head, placed her in his car and drove her into the woods. She was able to get away from Jamie, but after catching up with her he beat her and placed her in the trunk of his car.

Jamie then called Michael Ames who arrived in the woods that night with Terry, who he had been having an affair with. Jamie is overheard saying he tried to kill her but couldn't and asks Michael for help. Terry ultimately gets into Jamie's car and drives it into the lake, not knowing the girl was her niece Rosie.

CBSNews.com spoke with Allman at the beginning of the series' second season, when she said if she found out she was the killer she wouldn't be too upset.

"I would love to be the killer, not because I want to be a murderer, but as an actor you are always wanting to find things to act," said Allman. "[Playing] the girl next door that's smiling all the time may be fun for some girls, but it's not for me."

Though, when she found out it was actually her the actress told USA Today she started crying because she was sad for her character.

"I didn't expect it after episode 12, in which they insinuated that Jamie Wright was the killer. I had no idea at that point," said Allman to the paper. She found out she was the killer a couple of hours before the table read for the season's final episode, according to The Hollywood Reporter.

"The Killing" was based of Danish series Forbydelsen, but ended differently than its counterpart.

Tell us: What did you think of "The Killing" season finale?