Chief’s Counsel: The Mosaic Theory and Electronic Public Safety Technology

Everyone has heard of the saying that “the whole is greater than its parts.” The mosaic theory attempts to apply this basic proposition to the Fourth Amendment. Generally speaking, what a person puts into the plain view of the public is not considered to be protected under the Fourth Amendment.1 If an officer could have manually conducted surveillance of an individual while that person moves about on a public thoroughfare, then the Fourth Amendment arguably is not implicated and the officer would not have to obtain a warrant. However, under the mosaic theory, the continuous and persistent electronic surveillance by police of a person even in a public area does in fact implicate the Fourth Amendment because the cumulative data obtained by heightened surveillance creates a much more detailed and comprehensive picture of the subject—a picture that actual physical surveillance could never construct, which includes or excludes highly personal and confidential habits that the individual and some sections of society consider as an invasion of a person’s privacy and autonomy.