Exploiting quasi-random assignment to NYC arraignment judges with varying propensities to detain, we use a judge fixed effect instrumental variable approach to estimate the impact of pretrial detention on several case outcomes: guilty plea, conviction, and carceral sentence. We find that any period of pretrial detention increases the likelihood of a guilty plea by 23 percentage points, a conviction by 24 percentage points, and a carceral sentence by 35 percentage points. Stratified analyses show differences in the size of the effect by charge severity and race: felony defendants experienced a larger effect on all case outcomes; non-Black defendants experienced a larger effect on guilty pleas and convictions; and Black defendants experienced a larger effect on carceral sentences.