Shortly after, I got an Email from an unknown individual who said he knew the employee and asked if I could chat. Turns out, my employee was subbing out all of his work and stopped paying his sub, who then stopped delivering. The sub proved this to me by confirming some confidential information that he shouldn't have had access to.
After revealing that he had taken part in this scheme, the sub then asked me for a job! Needless to say I told him he wasn't a good fit.