Pretrial publicity (PTP) can bias jurors' decisions. The courts often assume such bias can be ameliorated or reduced by jury deliberations. This study explored the effects of PTP (antiprosecution, antidefense, or no-PIP) and jury type (pure vs. mixed) on mock-jurors'/juries' (N = 495/96) verdicts, impressions, and trial evidence interpretation. PTP affected predeliberation verdicts, with antidefendant PTP jurors being the most likely to render guilty verdicts, and antiprosecution PTP jurors the least likely. At the jury-level, only the pure antiprosecution juries (all jurors read antiprosecution PTP) showed evidence of PTP bias by being the least likely to render guilty verdicts. Comparison of pre- and postdeliberation verdicts revealed that deliberating on pure juries increased PTP's biasing effect on verdicts (group polarization) of antiprosecution PTP jurors. and resulted in more biased credibility ratings for antiprosecution and antidefendant PTP jurors. Regardless of jury type. no-PIP and antidefendant-PTP jurors were less likely to vote guilty after deliberations than prior to them (leniency shift), and their postdeliberation verdicts did not significantly differ. Finally, deliberating on mixed juries resulted in the transfer of PIP-bias from antiprosecution PTP jurors to no-PIP jurors. Implications include that PTP biases jurors' decisions and impressions, and the effect of deliberations on PTP bias may depend on PTP slant, jury type, and case type. Deliberations can increase bias in PTP-exposed jurors deliberating on pure juries and spread PTP bias from PTP-exposed jurors to those not exposed to PTP, but additional research is needed to better understand the circumstances under which each occurs.
