As soon as I read "I have been asked to use my drone to ..." I knew that it was a part 107 flight. My answer would be, "Yes you can do it. Just get your part 107 and you can do jobs like this any time you are asked."
Fly safe. Fly legal.
These LEOs need further training on drone regulations and laws.
Looking at the LAANC approval he was approved as a Part 107.
The next statement from the LEO should have been, "I see here that you are a Part 107. Please show me your Part 107...