Recommended Uniforms
Though most police service providers offer investigative services, indeed with the nature of Imperial Crime, few criminal acts require police response, the outcome of nearly any failed crime being either a dead criminal or an fleeing one. Many citizens however choose to augment their investigations by hiring professional investigators, who are typically much more likely to solve these issues. They don't dress much unlike your typical Adrian, better to blend in.
Finally the most important line of defence against criminal elements, the first and last for every citizen, the individual citizen and their firearm, the citizen in the Empire is not subject to bureaucratic police forces beholden only to the laws of the nation. Each individual has all the same powers as a police officer if granted in court of law, though of course most allow the professionals to do their business.