Which has been the hardest case to solve?

[Jonetta]

I thought Visions in Death was hard to solve. (view spoiler)[It took me a while to figure out the psychic was thwarting the investigation efforts. (hide spoiler)].

[Patricia]

I just finished Visions and I felt the same way. I didn't see that coming.

[Dee]

I think NY2D was the hardest, there was so much emotion, she didn't have her regular team, and McQueen, though no fault of the officers, kept getting away.