Moleface was the one that killed Toby and framed Alex. Moleface is also described as being even more cruel than the rest of the Blacksuits. He is also just a bit smaller. The reason Alex nicknamed him Moleface, is because of the prominent mole on his chin.
Alex and his friends were jumping into the river on their way to escape. Just before Alex jumped, He was attacked by Moleface, and was pinned down. Moleface grabbed a large rock and got ready to smash Alex's head with it. He failed to do so, because a horribly burned Blacksuit started choking him. After Moleface was successfully strangled, the Blacksuit was revealed to be Monty; who died shortly after. Alex was then free to escape.