Distinguishing peer from non-peer across the criminal justice sector: A taxonomy differentiating peer roles grounded in the insight of those with living experience of the peer mentor role in prison.

Amongst a variety of peer involvement and service user engagement roles, designed to realise criminal justice policy revolution and penal power re-alignment rhetoric, the peer mentor has garnered particular attention. What constitutes a peer from a non-peer remains undefined. Aggravating this uncertainty is a current lack of distinction made between different peer role profiles. We present qualitative residents-in-prison data drawn from an evaluation spanning four UK prisons. Residents-in-prison clearly distinguish their peers as those with living, rather than lived experience of custody. This is an original and important finding. We argue it is the shared synchronous living experience of criminal justice sanctions that constitutes the manifoldly transformative potential of the distinct peer mentor role. The Ministry of Justice's One HMPPS policy drive to consolidate practice indicates this uniquely dynamic definition of peer-ship status has implications beyond the custodial sector in which it is generated. Distinguishing between living and lived experience may have broader implications beyond the peer mentor role.