Sal Butrell is a Hasslich (a troll like creature) and was a senior official on the planning comity. Following his kinds traditions he bullied and extorted the Eisbiber's (harmless beaver like creatures) who were the constructors (there most common occupation).
He met Robert Grosszahne, the leader of Eisbiber expecting him to pay, however Grosszahne tried to stand up to Sal, and for that he murdered him. He was spotted by another Eisbiber, but terrified of the Hasslich vengence he did not tell. The murder led Nick and Hank to Sal, although they couldn't prove him as the murder, Nick saw him reveal his true self and thus Sal recognised him. Realising that as Nick was a Grimm he would come for him, Sal called in the Reapers to kill Nick. However the Reapers didn't trust Sal, and kidnapped him to ensure his story was truthful. Nick, along with his Eisbiber friend Bud, finally managed to convince the Eisbiber to come forward, and confess it was Sal. As such Sal was arrested, later Nick came to visit him, and revealed he had killed the Reapers Sal had called, calmly stating "they just lost there heads."