As bodies mandated by governments, truth commissions constitute a form of "official truth-seeking". Thus they can provide proof against historical revisionism of state terrorism and other crimes and human rights abuses. Increasingly, supporters assert a "right to the truth" that commissions are well placed to carry forward. Truth commissions are sometimes criticised for allowing crimes to go unpunished, and creating impunity for serious human rights abusers. Their roles and abilities in this respect depend on their mandates, which vary widely.
One of the difficult issues that has arisen over the role of truth commissions in transitional societies, has centered on what should be the relationship between truth commissions and criminal prosecutions.
In general, truth commissions issue final reports which seek to provide an authoritative narrative of past events, which sometimes challenges previously dominant versions of the past. Truth commissions emphasizing "historical clarification" include the Historical Clarification Commission in Guatemala with its focus on setting straight the former military government's version of the past, and the Truth and Justice Commission in Mauritius which focused on the legacy of slavery and indentured servitude over a long colonial period. The Commission for Reception, Truth and Reconciliation in East Timor also aimed to tell a new "national narrative" to replace the version of history that had been prevalent under foreign rule.
Within the scope of transitional justice, truth commissions tend to lean towards restorative rather than retributive justice models. This means they often favour efforts to reconcile divided societies in the wake of conflict, or to reconcile societies with their own troubled pasts, over attempts to hold those accused of human rights violations accountable. Less commonly, truth commissions advocate forms of reparative justice, efforts to repair past damage and help victims of conflict or human rights violations to heal. This can take the form of reparations to victims, whether financial or otherwise; official apologies; commemorations or monuments to past human rights violations, or other forms. Reparations have been central, for instance, in Morocco's Equity and Reconciliation Commission.