Brooks publishes widely on criminal justice and sentencing. His "unified theory of punishment" is noted as one of the top 100 Big Ideas for the Future in a report by RCUK. Brooks has written three books, edited two reports and 23 collections, published over 130 articles and 150 columns. His research on capital punishment is quoted and cited by the Connecticut Supreme Court lead decision in its case of "State v. Santiago (Santiago II)", 318 Conn. 1, 105 (2015) abolishing capital punishment in Connecticut. In 2015, the Electoral Commission quotes Brooks in support of its proposed changes to the EU Referendum. They proposed changing the ballot choices to "Remain" and "Leave" and this was later accepted by the UK Government.