Advice?

Me and my fiance just bought are first house. After around 5 days moved in, looking through everything I found extermination tools in a tupper ware box for roaches(boric acid). Even though we had left pizza boxes in the kitchen and dog food, still no activity. However, this instantly put me into alert mode, because we almost moved into an apartment that had German roaches. I instantly called an exterminator, they said since we didn’t see any live activity they’d put glue traps under the kitchen sink and in the basement behind the washer and dryer(the basement area and kitchen are directly under each other. Me and my dad moved the stove (seal off a mice hole) and replaced it looked behind it saw nothing that signaled any activity. I then found a dead brittle, almost see through, legs missing, antennas missing and half its body gone roach in the linen closet outside of the upstairs bathroom. 3 weeks after moving in the exterminator came checked the glue traps, we saw nothing not even an ant. However when he was helping us with the mice problem he noticed in our extremely old dishwasher that hasn’t been used in probably years that there was history of past activity. As a precaution he sprayed a barrier thing called “patrol”. He said “don’t be scared” but if you see a live one call me immediately. Do you think this was a past issue or still on going? Before we owned this house it was owned by a flipper who had it for 5 months, however, before them it was a hoarder.