Fans of The Office have often speculated that Kevin embezzled money from Dunder Mifflin, as it was implausible that he would buy an entire bar after getting fired from the office. Kevin invented a new number, the Keleven, which could be said alludes to him stealing money from the company with his questionable accounting practices.
Kevin's gambling addiction also leads him into trouble a few times throughout the series, and Michael goes to him for advice on rigged fights, which Kevin might know about if he were ever to turn to crime. Kevin has mixed results when keeping secrets, but did manage to keep Oscar's secret about the state senator, so perhaps an undercover life of crime isn't too unfeasible for Kevin.
Michael did actually break the law several times during the series, such as when he hit Meredith with his car and organized an illegal casino night in the warehouse. Michael also did drugs and almost got busted -- even if the only one who cared about that was Dwight -- and framed Toby for having drugs but got out of it when the police actually turned up. Michael also sometimes romanticizes crime, pretending to be Agent Michael Scarn at improv and in his movie.
Michael would do anything to be the center of attention, and would definitely try to spin the perception of the crime in his favor. It is unlikely that Michael would do an outright crime unless it was by accident, but if one of his friends asked him to participate, it is also unlikely that he would say no.
Robert California absolutely has a shady past, as California is not even his real name. Robert has extraordinary power over other people, convincing the Scranton branch to make him manager, unnerving Dwight with just a look, and convincing Sabre CEO, Jo Bennett, to give him her job. What else could he convince someone to do if he were in the mood to commit a crime?
In many ways, Robert was actually a good CEO and had no qualms about knowingly running a company that sold subpar products. He also stokes trouble quite a lot, telling a scary story at the Halloween party that shocks everyone, and often playing mind games with Andy and Nellie.