I disagree with the other responses. It's a simple question of practicality. If we entrusted attorneys with both criminal defense and prosecution on some kind

I disagree with the other responses. It's a simple question of practicality. If we entrusted attorneys with both criminal defense and prosecution on some kind of ad-hoc contract basis, there'd be way too much temptation to mix things up in an illegal and unethical way. You'd have the ability to discern the prosecution's case on a case you're defending, and to a lesser extent the reverse. You'd be able to make all kinds of deals through horse-trading that make the current plea-bargaining system look half-respectable. It's not a yin-and-yang sort of situation with representation either. All government attorneys should be on the same team, but defendants often have conflicting interests (which one of you had the murder weapon?) that can often make the most contentious parts of the case take place between defendants. Prosecutors enjoy unfettered power to the point of being above the law, and defense attorneys do not. Until that changes, it doesn't matter who shuffles between the job titles. One other aspect of the original article- like many defense attorneys, this one was a former prosecutor. One major reason for the change is an increase in income. Even if no such ties actually exist between the newly transitioned defense attorney and their former chums at the state attorney's office, they trade on such ties and judges will treat their clients colored by such ties. It's a corruption in the system, one among many. DISCLAIMER: I've been represented by both an ex-prosecutor and non-ex-prosecutors.