The guys from "Connect The Dots" are going to be main characters for an episode
Maybe one of them has a falling out with the other and decides on murder...
Charlie's lie-detecting still works in other languages.
It may not be obvious yet but even if Charlie doesn't understand a language, she can still somehow tell when someone is lying. The problem, of course, being how she figures out what's being said before she can unravel the lie.
Charlie will encounter a killer who is a serial liar in Season 2
Sounds like that'd make it easy for her, right? Well, not really, since they'll tell so many contradictory lies that knowing what they're saying isn't the truth won't actually help much at all.