I am be over stepping here but anyway...
The best training for forensic nurses is to start out as a sexual assault nurse. They are widely accepted (for the most part) and the majority of police know about us. Also be careful about where you get training. Their are a lot of online programs out their that cost a fortune and don't offer much of hands on experience. The best place ( in my opinion) is the IAFN website. They have programs listed all over the country.
The biggest problem I have found is education and people being resistant to change. I started working as a reserve police officer. Other officers respect that and it gets me loads of "street credit". I look just like a regular police officer (gun and badge too). It is however free work but only 12 hrs per month. I do their CPR classes, annual sexual assault and child abuse inservices. I have also started to branch out in legal nurse consultanting and death investigation.