Here's the procedure from the walkthrough, double check against this and make sure that you have the fingerprints on the lab report:
Obtain a search warrant on Peter Hamlin.
(A) Access the six folders and click on the search warrant tab.
(B) Drag your suspicious person (Peter Hamlin) into the “Suspect” window.
(C) Drag into the box marked “Supporting Evidence & Witnesses”, whatever icons you think are necessary. (Should be {i} Peter Hamlin’s background check {ii} Access card lab test (after Hamlin’s prints are on it !)).
(D) Click on “Submit” … If you want to repeat, click on “Clear”.
If correct, you are inside Peter Hamlin’s residence.