Dr Johann Koehler

Assistant Professor

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About

I joined the LSE as an Assistant Professor in 2019, and I have been the Director of the LSE’s Mannheim Centre for Criminology since 2024. My chief interests lie in the origins, applications, and limitations of the movement to pin criminal justice to robust science — what in some circles is called ‘evidence-based’ justice reform.

Origins: In one line of research, I trace the progressive history of scientifically-informed criminal justice policy. Since their earliest years, criminologists have argued that criminal justice policy ought to rest on sound evidence. I study what lessons we can take from how that case has been presented, and what its policy effects have been.

Applications: In my second line of research, I evaluate the steps that could be taken to align criminal justice more closely with evidence-based principles. To that end, in my recent work I help identify which interventions are most likely to yield desired results, and I appraise the extent to which current practice rests on — or departs from — the policies we believe promise those results.

Limitations: In my third line of research, I study what the call for evidence-based policy does for us, and also what it does to us. Although basing social policy on good science holds intuitive appeal, that policy stance also provokes thorny — and deeply consequential — questions about what kind of criminal justice we want, what we’re likely to get, and how we’ll get it. I analyse the potential of that policy stance, and also its perils.

These themes coalesce in a book project on the historical sociology of evidence-based criminal justice policy reform in the UK and the US.

If you’re passing by the Social Policy department and my office door is open, then please feel free to stop in and say hello!