There was a scene, when the Obscurial destroyed one of the buildings, this one where the Niffler (which stole all the gold from the movie) was hiding behind paiting/picture on the wall and they all were attacked by the Murtlap from the case.
After that, police came and asked witnesses if it was a gas explosion and one of them, while trying to say that it was caused by magic got affected with a spell casted Newt.
It was a strange spell that was 'sniffed' by the witness and I remember only one similar scene from HP, in Gringotts, when this spell was used on one of the Goblins when Harry, goblin on his back, Hermione (transformed to Bellatrix) and Ron were trying to get into the bank and as I remember well - it was Imperio.
Was this spell in Fantastic Beasts Imperio too? If so, why? How? Was it 'legal' those days? :D