knowing the police departments they'll make up all sorts of bullshit requirements and end up spending $8500 per camera made by some police chiefs brother in laws company.
Now, I don't own a GoPro, but last I heard, they were nearly indestructible inside their shatterproof sealed case. Unfortunately, without the bulky case, they're left rather vulnerable. A wearable camera is going to have to be comfortable and not interfere with movement, so it will likely need a different form factor.
If the GoPro (or other COTS) offerings don't meet that one legitimate requirement for the job, then something else will have to be found. The search will have to include the other "bullshit" requirements that GoPro already meets: Shock resistance, operating temperature range, battery life, et cetera. For an established manufacturer, it will involve some engineering, but for a newcomer to the field, the engineering will be quite extensive and expensive, especially since that engineering cost is spread over relatively few units, whereas a consumer-oriented product like GoPro can expect a few million sales.
Of course, understanding those many requirements, especially ones like "fits comfortably during officers' regular duties" requires a keen understanding of a police officer's life. Naturally, those who are already familiar with the use case will have an advantage in meeting those requirements satisfactorily. That means the best product will usually be designed by an established company who's built a good working relationship, or a newcomer already familiar with the needs, like a family member or friend.