How do encounters with persons with mental illness differ from encounters with persons without mental illness?
Responding to calls involving those with mental illness can take much more time than other calls to service. This can be a drain on a police department's resources partly because additional specialized training is necessary. Officers may also have repeat contact with a particular mentally ill person. These repeated interactions increase the odds of encountering volatile situations that can escalate, risking the safety of all of those involved. The majority of the encounters with people with mental illness are those that see them committing some kind of nuisance behavior that may not be a crime at all or, at most, it's a low-level misdemeanor-type crime.
The real issue resides in the fact that the officers can frequently end up returning to the same location throughout the year, meaning that the problem giving rise to the call is not resolved in the long term.
The persons with mental illness are generally more challenging for police officers to take into custody. However, in terms of outcomes, police officers themselves don't experience injury with any greater frequency than with dealing with the general population. Other parties that may be involved with an incident concerning the mentally ill are also not exposed to any greater risk than in incidents involving the general population.