That's about the same level of need advocates were predicting when they pressured the O'Malley administration into agreeing to this study last year. At the time, administration officials suggested that if those numbers were borne out, they might build a facility of the same size as the one now planned but repurpose some of it for other uses. That would be a mistake. For one thing, if we don't have to spend $100 million, we shouldn't, particularly at a time when so many other needs are unmet. And it's unclear what other uses would be appropriate in a jail located in the middle of Baltimore's downtown prison complex. If the state builds a big jail, it will eventually fill it, quite likely with offenders who aren't a good fit for the space. The troubled history of Maryland's juvenile justice system proves the necessity of designing facilities carefully for the purpose for which they are intended.