If you try to do something, you make an effort or attempt, which may well not succeed. Indeed, when we are talking about past attempts, we often imply (or state explicitly) that it did not succeed:
I tried to open the window, but it was stuck.
If you try doing something, you actually do it, in order to see if that brings some satisfactory result. We don't know until afterwards if there will be such a result:
The room was very stuffy. I tried opening the window - 1. but it didn't help. 2. and it helped a little.
In your example, they will actually search.
Student or Learner