There are so many layers of thought and discussion that could be explored from even this one small part of your query.
There are always those, in every group, that beat down and attempt to destroy those not like themselves. I would wonder if some of the punishment that they inflict, on some level, is not punishment they feel for themselves.
Look at the movie "A soldiers girl" Did not the instigator that got Berry killed have Tran issues of his own? I cannot answer, in general, to your query. Each encounter between the police and a trangendered person must be looked at individually.
What caused the eye of the law enforcement sect to fall upon the transgendered person in question. Being TG alone in not a crime, however there are alot of TG's that have fallen into the SEX-CRIME melting pot.
No one likes to have a police office encounter except those that seek it out. I have in the past conducted a traffic stop that involved a TG/CD/TS person and they got treatment just like any other citizen. In fact, they were treated by me according to their expressed gender, regardless what the drivers license told me. I doubt very much if this courtesy would have been extended to them down at the jail by either sex on either side of the iron bars.
In a group of cops however, I doubt that even this little bit of human courtesy would be expressed. i wonder... suppose that two closet TG cops working together came upon a Cross Dressed Driver. Since most of us TG's have led secret lives and have become very skilled at playing roles and wearing masks, I also doubt that the driver would get much courtesy. In reality the driver would probably get a homophobic and perhaps a homocruel response as part of role either of our two cops may play.