IN LATE January 2012, District Attorney Seth Williams opined that "greed" drove a dentist and his daughter to defraud insurance companies out of nearly $5 million.

"This is a case that only happened because of greed," Williams was quoted at the time. "He could have continued making a more comfortable living than probably 98 percent of all Americans as a dentist, but because he saw this as an opportunity, he took it."

Two weeks later, Williams and his girlfriend were on their way to a luxury resort in the Dominican Republic for a vacation, allegedly paid for by a businessperson in exchange for favors from the D.A. That's part of a 23-count indictment against Williams released this week that includes honest services fraud, wire fraud and bribery-related charges.

In November, while vacationing in Maryland, he spent money in a restaurant and supermarket, allegedly from an account earmarked for his mother's nursing home care - an account from which he ultimately looted over $20,000 for his personal expenses, according to the indictment.

Two weeks after that vacation, Williams cited "greed" again as the motivator for contractor Griffin Campbell, arrested for his part in the shoddy demolition of a building at 22nd and Market that collapsed and killed six people.

These are just a few samples from the ironic contrasts between Seth the District Attorney and Seth the Big Spender, drawn from a long list of the numerous gifts, cash and travel accepted by Williams from 2012 to 2015, laid out in this week's 50-page indictment. That indictment claims that what Williams reaped, he returned in the form of favors and offers to use his office to help associates with legal and criminal problems.

He has pleaded not guilty and presumably will fight this in court. He already was handed a whopping fine for failure to report an entirely separate set of pricey gifts, and the city might try to recoup the legal expenses it has paid to date for his legal defense. Given his money woes, it's not clear he will resign - although he should. It's impossible to imagine how the D.A.'s office can work effectively if he remains at the helm.

In the face of these charges, we are struck with a number of questions: What was he thinking? How can a $200 tie be worth compromising the credibility and trust of the D.A.'s office? When Williams loudly proclaimed these cases of other people's greed, did he feel the slightest twinge of discomfort about his own apparently unquenchable thirst for luxury gifts? How can there be such a stunning disconnect between his public life - as a fighter for justice and reform - and his private choices? That's the heart of the mystery for many of the fallen elected officials who have come before him.

This is not the first instance of public officials falling from grace (Chaka Fattah, Vincent Fumo), nor will it be the last. That leads us to wonder: Are there larger questions we're not asking about the people we elect that might prevent more cases like this? Is there something about public office that fosters entitlement and arrogance in certain people?

We'd like to imagine the indictment prompts some soul searching on Williams' part.

Unfortunately, much of that could be happening in federal prison.