There are many, but capital offenses have no limitation, and there are many potential capital offenses. However, that shouldn't really be an issue here, because any business can commit a capital offense, but we don't require every business to record every bit of information about everything they do in perpetuity just because they might commit a capital offense one day. Innocent until proven guilty.

I think that there is a limit on the required period of record retention but I keep failing to find it.

But I don't think it is short, and it at least extends as long as you are selling the material to which it relates, since it is expressly illegal to sell depictions without the records.