If I did that and I was renting, I would of course deny doing anything.
It is possible the tenant did not do anything, thus the reason for gathering information from the power company, neighbors, and the electrician.
I'm not a lawyer, so don't know if tampering with this would be against the law or not. Plus I would want evidence that someone did something before calling the police. -> Gather evidence first.
Maybe it is just a case of retaining a damage deposit? But still I would want documentation.
Yes call an electrician and he may get the permit for you or advise you on how to proceed.