Forensic Photographers
Forensic photographers are usually employed by the Poilce or Forensics to take photographs at crime scenes and accidents to use as evidence or as records of the incidents.forensic photographers need to be skilled in order to make sure every aspect of the incident is photographed, for example if there is a crime scene where someone is attacked, it is important that finger prints left, blood marks and footprints ect are all photographed as evidence for court and it could be really significant if something like this was missed by a forensic photographer.
Forensic photographers usually start their career as forensics, this is because they become wise in what to take pictures of and are used to the type of scenes that they might see as the photographers usually take imagery of dead bodies and assaults, therefore the job could be quite distressing for any photographer to walk into.

I found this information on creative skillset where there are more details that come with the job
http://creativeskillset.org/