[nascarfan999]

I had a chance to listen to the audio from the role call, and here is my take...

Around 9:20-9:23, there are a couple instances of tones going off over the channel. Without being a regular monitor of Columbia I cannot say what these tones are, but the 2nd of the tones may be the initial cause of the role call (see below).

Around 9:24PM (8 minutes into the 9:16-9:30 tape), the dispatcher contacts SR4 inquiring about the units with SR4 and their radio status. SR4 then inquires to dispatch whether this is due to an emergency button going off. The dispatcher replies that there was a "partial activation." Once it is determined that it did not come from SR4 or the unit(s) with SR4, the dispatcher then starts the role call.

My interpretation of this is the 2nd tone (a very fast two tone that is repeated 3-4 times) may have been the activation of the emergency button on a radio of a unit (likely accidental). Some of these systems have the capabilities of determining which radio (and thus which unit) pushed the button. Based on the dispatcher's phrase of "partial activation," my inference is the dispatcher received some information to believe SR4 was the source of the activation. Once it was determined this was not the case, then a full role call was completed. As for the extra units, in other situation I've heard, a role call like this would include EVERYONE who has a radio equipped with the emergency alert button (likely everyone with a radio). This would include all road officers and supervisors, detectives and other officers not normally on the radio, animal control, and corrections officers (if Columbia has a city jail). In addition, some non police units may also have radios. Examples I've seen in the past include building inspectors and street department units. Now, given the time of day, I wouldn't think many of those units would be on duty at the time. One last possibility would be any Mizzou security officers. I do not know what kind of communication capabilities the university has with the PD, but if they have radios they would also likely be included in the role call.

I know this explanation isn't 100% foolproof, but I feel it is the best explanation possible at the time.