"Nifong requested the swipe card data for a limited time period, maybe 24 hours"
Ummm. . . isn't it a little late for him to start investigating this case? Don't you decide who to charge
AFTER you find out who did the crime and get the evidence?
(Sorry, but I'm not too familiar with police work.)
It is not unusual for an investigation to continue after indictment. A legit prosecutor might find in- or ex-culpatory evidence and make a decision to drop charges on the latter. I know this is a theoretical point with Nifong involved, but it is not unusual to continue an investigation after an indictment.
Yeah, you've got the sequence right. Investuigate, THEN arrest if you've got the goods.