What type of training is required to become a crime scene investigator?

For crime scene investigations I would major in science. Also you can find some vocation schools and sometime degrees in crime scene investigation which can help.

In Canada with my Police Service, we take experienced police officers and send them on a 9 week training program at the Ontario Police College or the Canadian Police College. They learn to take fingerprints, photography, crime scene processing, gathering DNA, reading blood spatter, and many other subjects. This is their basic course. They then go back from time to time to take on going training to give them expertise is certain areas like arson, tire and foot impressions, etc. We also have civilians that for the Centre of Forensic Science in Toronto and Sault Ste Marie, Ontario. These are civilians who have University degrees in science and are specialists and experts with Master and Phd degrees in areas like Physical Anthropology, Toxicology, Biochemisty (DNA) and many other areas we send things to them to process. There are some Police Services that have civilian Forensic personnel like you see on CSI. We did have one once but he left for another police service. They have the same training as the officer without the police experience and usually a degree in Forensic Science from university.