Simmons' expertise is in the field of criminal procedure; specifically, how the law of search and seizure should respond to advances in technology. He has also written on the grand jury and the privatization of the criminal justice system.
Discusses the ways in which the adjudicatory aspect of our criminal justice system has become privatized. Argues that greater privatization would be a net benefit for all of the stakeholders in the system.
Proposes expanding the binary search exception to the Fourth Amendment to allow for new uses of investigative technology that are not as invasive but which can provide valuable information to law enforcement.
Critiques the "special need" exception to the Fourth Amendment and argues that the government is relying too heavily on this exception in its terrorism investigations.
Applies economic theory to criminal procedure law and proposes changes to search and seizure rules based on that application.
Argues that prosecutors should use the grand jury more effectively in cases involving police lethal use of force. Proposes greater transparency rules for the grand jury to effectuate this change.
Discusses how police use of big data analytics can be used by prosecutors and courts in deciding how to legally proceed with criminal cases.