Do police departments use the services of certified handwriting analysts?
Police Departments use forensics specialists to determine the true identity of ransom notes and other handrwritten evidence. They hire or use in-house trained document examiners (see: http://handwritinguniversity.com/docexam). However, any government agency is not going to pay as much as the private sector. You are not going to get rich working for the government. In many homicide cases and FBI cases such as cases involving serial killers, a handwriting analyst is hired to help establish the psychological profile of the suspect if handwriting is available. The FBI has people on their staff for this purpose, with special criminal science background.