CQ, it can be either. When I was with a firm that did a lot of white collar work, the second arrangement you describe was more common (that is, monthly replenishment of a retainer against which hourly fees were billed, just like in civil cases). There can be a number of reasons why the first may be used, however. If there's a chance that assets in the client's name may be seized or frozen, it's obviously in the firm's interest (and often the client's) to secure as much payment as possible up front. Also, as Lester points out, once an actual case has been filed and the attorney/firm is official counsel of record, judges are sometimes reluctant to let the lawyer out of the case. Again, that's a reason to try to get sufficient payment secured in advance. Also, in cases where the defendant is a corporate employee, officer, or director, there may be certain issues implicated in terms of payment of legal fees by the employer or an insurance company. There can be a great variety of scenarios, but suffice it to say that if there is a concern that the payor may stop paying at some point, there's an incentive to get as much money committed early as possible. Also, in some situations the firm may request a large up-front, non-refundable ("earned upon receipt") retainer, which may have advantages in the the event of a forfeiture of assets or bankruptcy. I agree with Lester that avoiding an indictment that otherwise would be filed is the exception without the rule, but I do believe good representation can often make the difference between being indicted or not in cases that are on the border. At the very least, it can make the difference between an unpleasant outcome and a catastrophic one.