Can I get work like Roth's?
Of course. It's simple. Spend fifteen or 20 years learning everything you can about locating people, bounty hunting, repo work, insurance law and adjusting, product liability, rules of evidence, security-perimeter and executive-surveillance and technical surveillance,arson, photography, surreptitiously recording, eavesdropping devices,TSCM (technical security counter measures), medicine, forensic medicine, drugs, criminal and civil law, penal measures, accounting-forensic accounting would also be a plus-executive protection, management software, weapons, interviewing and interrogation, and litigation. Throw in a couple of divorces, and if you're married, be prepared for one. Simple.
A lot of people believe that they have the skills for this work and many do and can develop them easily enough. But the thing they overlook is the nitty-gritty, day-to-day grinding out results. PI work is a lot of things, but firstly, it's a business. And many aspects are routine to a numbing degree. It's like any profession; anything worth doing will likely take a lifetime to master. Like any endeavor, it's not something one should take up lightly.