The RCMP carried out a study in 2001. I'm not aware of studies that other police forces or organizations may or may not have carried out. I know that there have been studies, but I can't give you an exact figure. There have been hundreds of studies. The conductive energy weapon is the most studied law enforcement device in the world. It has been studied and reviewed more than any other device to date, but I can't give you any exact figures.
On February 25th, 2008. See this statement in context.