On April 16, 2020, the Massachusetts Supreme Court issued a decision that may likely set the standard for the use of digital technology in criminal cases. The case is Commonwealth v. McCarthy (SJC-12750), and involved the tracking of an individuals movements over a period of time by use of ALPR cameras (license plate recognition). The opinion is a must read for law enforcement, particularly detectives, police supervisors and any others who may be using digital applications to track (or to look back at) the movements of individuals.
Some important highlights:
the court gives a good overview of the history of how use of developing technology will result in a constitutional search - incuding cell phone, GPS and Automatic License Plate Recognition;
affirms that while a particular instance of digital surveillance might not, alone, be a constitutional search, the piecing together of a larger digital picture likely will be (i.e. looking at movements and patterns on GPS or ALPR, etc.);
when analyzing whether a constitutional search took place (which would need a warrant and PC), the court made clear that it will consider not just data ultimately sought to be used by law enforcement, but also what data was requested or even looked at - in other words, the entire scope and duration of the data search;
the court will also consider location of the surveillance, for exampe license place cameras placed in senstive areas (residential, near religious institutions) will be scrutinized more than those on highways, etc;
importantly, the court suggested that police will need to preserve every search query it makes regarding an individual (not just those that resulted in useful data) and also must share that information in discovery.
The opinion goes into a good history of the evolution of surveillance technology and its effect on the expectation of privacy. Again, it is a must read for criminal investigators and detectives.