It would work... only if the fetherals and SWAT team itself believed him.

You see, Trousers has a big reputation on the city. Everyone knows and likes him, he's charming, has humor, is gentle, is a character of the city, does a very great job with the patients and has a record of excelent works done with diamond shinning results. He's a genuinely skilled doctor and patients trust and like him, just like anyone around. No one would suspect anything about him, not even the police. His image is clear

For a SWAT to happen there must be a permit from supperiors to consent the break in, with the reason of acting against an open critical case registered. There must be a bit of research done on the case from them so there is a legal reason to do so, SWAT is an action taken when there is potential risk... and there is no case open about Trousers. "Why would it? About that one nice doctor? Dr.Trousers?? You must be crazy, he helped half of the city to go through at this point!"

Gray is in no position against Trousers's public recognition, no one would believe him when doing such accusations towards such a generous and nice guy that helped so many people. Meaning that not even the police themselves would be near from opening a case to prove if the doctor of the town is sEcRetLy a mUrdeRer, (that guy cured the officer's son!)
Sounds quite ridiculous don't you think? 

Also thank you a lot