AndiLA, i believe it was 1994, i can double check my docs for exact date, that the last mobile phone was manufactured that did not have tracking capability when powered on or off (as long as the battery is not completely dead). regardless, it is a non issue since 99% of mobile phones now are digital, either GSM/CDMA/IDEN and a few straggling TDMA's. especially with the GPRS system being put into place sometime around 1999 there is no need to 'ping' a device. your phone constantly registers with the nearest tower, even when it is not turned on, this is why you can just pull it out of your pocket and start dialing. also if you will notice on your phone, it uses the towers to keep the correct time, etc. it is IMPORTANT that investigators look into TOWER logs, not CALL logs. the tower logs can show everywhere you have been since you have had mobile service, it updates every few seconds. sorry for the long explaination, i know its not totally related to the thread, but if you are interested in mobile networks, etc let me know I have tons of docs and we have a whole community of people who are always willing to share knowledge.
the most important issue related to the search is that ALL phones do this. so if the perp was carrying a phone, the logs will somewhat match that of Mickey's phone. keep in mind, because of the size of lafayette, i am sure upto 50 maybe more other phones may slightly match that of Mickey's but having 50 people to talk to in the hopes of maybe getting a lead is better than 0 people to talk to and no chance of getting a lead.
it is just a suggestion