His research showed that allowing victims to depose impact statements at sentencing promotes their welfare can also lead to more proportionate sentences without prejudicial effects upon the interests of offenders. Professor Roberts also conducted empirical research into Public Attitudes to Sentencing, using representative samples of the general public. People were asked to impose sentences in specific criminal cases, and to rate the importance of various mitigating and aggravating factors. The research showed a much greater tolerance than many had assumed for important mitigating factors at sentencing.
Roberts’ research has been used to better inform sentencing practices in several jurisdictions. In Canada, it has been cited in the Quebec Court of Appeal and in courts in Newfoundland and Labrador (e.g., Cook, 2009)to produce a greater sensitivity to victims’interests. His work on mandatory sentencing has been cited by the Supreme Court (Lloyd, 2016). Roberts’ research has also been cited by the Court of Appeal in England and Wales (Perkins and Ors, 2013) In England and Wales, the impact of Roberts’ research has come through its influence on, and use by, bodies that develop sentencing guidelines for courts. In collaboration with Professor Hough of Birkbeck, Professor Roberts conducted studies commissioned by the Sentencing Advisory Panel, one documenting public attitudes to sentencing principles and purposes, and the second documenting public attitudes to sentencing for driving offences resulting in death. Relying on Roberts’ research, the Panel produced more principled and consistent sentencing, and sentencing guidelines that better reflect community values. Finally, in the US, his work with colleagues at the Faculty of Law, University of Minnesota on prior convictions has been cited by US sentencing commissions.
Professor Roberts’ research has also had impact in judicial education. The Canadian National Judicial Institute invited Professor Roberts to be a member of a group constructing a national curriculum on the use of victim statements at sentencing. Alongside a judge from the Court of Appeal he co-taught three sessions to judges across the country. He has also participated in judicial education in Pakistan, England and Wales, Israel, and China.
In recognition of his research-based expertise, Roberts was appointed in 2008 to the Sentencing Commission Working Group headed by Lord Justice Gage and in 2010 to the Sentencing Council of England and Wales, a statutory body which headed by the Lord Chief Justice. Roberts is the only academic member of the Council and he was re-appointed for a third term in 2016.