They probably should've shown Sasaki alongside Honjou the few times she was on screen considering how important his role was as well. It felt like he was some random character the author just decided to insert in to be one of the suspects because of how little focus he had.
I'm guessing these the will confess and Wakatsuki is let go.
@Lithe "How could you possibly hurt the guy who's been hurting you? How cruel could you be?" /s