Lothar
SpoilerJagrun nodded. Reaching to one side of the desk, he picked up a folded piece of paper and handed it to Lothar.
"Please look at the symbol on that piece of paper and tell me if you recognise it. Only look at it as briefly as possible, and then cover it again."
Spoiler
"It was found painted onto the skin of the fourth victim in his own blood. Have you seen it, or anything like it, anywhere else in your investigations?"