Who Killed Joffrey? An Update

Why it could be him:

• Our newest suspect is implicated when he see that he had arranged for Ser Dontos to spirit Sansa away from the wedding (and that little bit where Dontos earns her trust in the premiere with a family necklace was also a ruse, courtesy of Baelish).
• Baelish, aka Littlefinger, is a schemer with a weak moral compass. He wouldn't shy away from being a kingslayer for some sort of gain.

Why it couldn't be him:

• Aside from him not physically being at the event, there's not a lot to indicate that Littlefinger is innocent, especially since he could have paid someone to do the poisoning for him.