Modern coins, circulation strike with DD? Hard to find. At mint they strike those penny at 750 by minute. One strike at 60 tone and the coin go, no second strike on same coin. the dies when are damage or are 85% of calculated strike life are change. On those actual times will we see some DD on specimens (2 or 3 strikes) and proofs with not more then 4 strikes.
To see exactly, because of the light reflection, I suggest to look through UV. Just pit the coin under UV and examine, there you will see exact.
MD for modern coins yes because of the speed of the production line. Theoretically if the line stop for one reason or other, DD will happened. But will be only one or some of center, then laser drive line will recalibrate her self.