Troopers say the first incident happened at the Walmart on Mill Creek Road in Lower Macungie Township back on December 7.
The second occurred about two miles away at the Target on North Krocks Road on Thursday night.
In both cases, the man seen in surveillance images reportedly groped women before leaving in a gray or green Honda sedan.
Officials believe there are more victims out there.
If you have any information on the crimes, contact Pennsylvania State Police.