Evidence collection and container sealing

OK - have a situation where I would like some suggestions. I am the Union Executive Steward for our ME office. Until 2012 investigators were instructed to collect and seal evidence as per the NIJ recommendations.. During a staff meeting management told them that they were not to seal the envelopes or gun boxes when they collected the evidence. Instead they were to bring them to the office then place them in an evidence locker so that morgue personnel could seal the evidence after the autopsy. An investigator followed the instructions at a suicide scene and one of the expended casings was missiing when his rlief investigator checked the evidence to place it in the locker. ( the investigators were also instructed to leave any property/evidence for the relief investigator if they were on overtime.) Now management wants to suspend the investigator.

My take is that this was a preventable accident that could have been avoided if the evidence was processed at the scene as per NIJ recommendations. It smacks more of holding the investigator responsible for a flawed policy. Suggestions and/or input appreciated.