Monday, March 25, 2013

The mosaic theory

From time to time, I blog about various technologies that collect and collate information about our daily movements and activities.  Some of these are investigative tools used by law enforcement, such as automated license plate readers. Some, like traffic cameras or toll booths, are operated by government for non-investigative purposes, such as monitoring and adjusting traffic signal timing or collecting fares.  Most, however, are not governmental at all: the access control software at your place of business, the cameras at the convenience store where you buy gas, the credit card that gets swiped at a coffee shop and the dry cleaners, the check of emails and the phone calls that traversed certain cell phone towers, and so forth.

When these small points of data are viewed together, you really can create a history of an individuals travels and activities over time. Increasingly, detectives try to assemble such information about victims and suspects in the most serious criminal cases, such as homicides. It has been a relatively recent, but dramatic addition to the investigators arsenal. In a presentation I did a couple years ago at Ignite Lincoln, I titled this new reality as "Nowhere to Hide." I am certain that we are on the verge of some real hand-wringing and soul searching about the loss of personal privacy that attends the explosion in technology that tracks our daily lives.

I read an interesting article on the state of the law of arrest search and seizure as it pertains to such data last week in the current issue of the Police Chief magazine. I recommend it to my law enforcement audience:

The Mosaic Theory and Electronic Public Safety Technology


Clean said...

Interesting article, Tom. I wonder where in the construct the use of non-governmental, non-technical observations would fall. While it may be unfeasible that law enforcement would persistently follow someone without the use of technology, it is entirely feasible that some other citizen could report on repeated activity of an individual because of placement. A shopkeeper could easily regularly observe and report someone regularly visiting an establishment across the street. Further, there could be a number of such observers. As the number of those increases, so does the possibility of assembling the mosaic. Is there some line here? Or is it only the use of technology that creates the consitutional problem?

Tom Casady said...


As you know, such observations by citizens have been reported to the police forever, and often help the police piece together information of a criminal enterprise. The classic example is the watchful neighbor who reports a lot of short-term traffic next door, and has been collecting times, dates, and license plate numbers.

These tidbits today, however, are contained in a database, rather than the black notebook in your back pocket, or the file drawers full of complaint forms. As such, the mosaic can be augmented by tips and information from the public much more effectively.