[ Security footage would be a smart move, but she has a hunch some investigative types among the group have already looked into that possibility. If they came up with anything, they would have reported it. As for her question... ]

Yes. It would have to be an incredibly powerful curse, but it's not outside the realm of possibility. A sorcerer could also do it if they're strong enough.

[ Though she's spitballing here. This city has zero residual traces of cursed energy, so that isn't likely the cause. ]