You wanted to know more about deep scans. Well, it's not something that I relish, really. One of my duties as the duly licensed commercial telepath on Babylon 5 is to serve as an expert witness in murder cases. The authorities may request my services to perform a deep scan of the guilty party, before the sentence of mind-wipe is carried out.
You see, we don't execute people for murder anymore, but they undergo the death of personality instead. Afterwards, the criminal is given a new identity and is trained to be a useful member of society. It's not pleasant, having to go inside the mind of a psychotic individual, but we have to do this, to ensure there's no unreasonable health risk, before the mind-wipe is carried out.
That's the only circumstance in which I'm entitled to scan someone without their permission. By Earth Alliance Law, we're not even allowed to use telepathic evidence during the trial; but only afterwards, to confirm the guilt of the convicted party. Of course, a person can request a deep scan voluntarily. Sometimes, I am asked to help people, who have suffered some kind of brain trauma, to recover lost memories.