A mistrial was declared in the case of an accused Rochester Hills drug dealer this month after it was disclosed his defense attorney never received pretrial information about a mobile tracking device placed on his client?s vehicle by investigators. But still in dispute —and possibly to be addressed at a pretrial hearing Tuesday— is whether the tracker that monitored his movements was legally attached to Dukes? 2015 Cadillac. Officials have been unable to locate the original search warrant reportedly obtained from a Pontiac district judge by Detective Charles Janczarek, a member of the Oakland County Narcotics Enforcement Team. Defense attorneys and civil right advocates said the case underscores concerns about the potential for abuse of GPS trackers by law enforcement and the need for proper search warrants.