Dateline: November, 2007, Issue 2
Recently, Hannaford and colleagues (2002) examined the causes of juror deadlock in 336 non-capital felony jury trials conducted in state courts in Los Angeles County (CA), Maricopa County (AZ), Bronx County (NY), and the District of Columbia (DC) between June 2000 and August 2001. Thirteen percent of these cases hung on one or more of the charges.
Juries that hung on at least one charge were faced with more charges, weaker evidence, problematic deliberations, and juror perceptions of unfairness. In cases that hung, jurors had greater differences of opinion about the credibility of police testimony, voted earlier in the deliberation process, struggled interpersonally with each other, and struggled more with jury instructions.
While weak evidence is by far the most frequent reason juries deadlocked (63%), juries rarely hung due to one reason alone; over 70% of the time, juries evidenced at least two, and sometimes more, reasons for deadlocking. Case complexity and dysfunctional deliberations often supported weak evidence as a reason for deadlocking. Similarly, police credibility and fairness concerns also often supported weak evidence as a reason for deadlocking. Dysfunctional deliberations consistently combined with all other causes of deadlocked juries.
In sum, juries that hang on at least one charge perceive the evidence as weak and additionally have either dysfunctional deliberations, fairness concerns, complex cases, or questions about police credibility.
Source Hannaford-Agor, P. L., Hans, V. P., Mott, N. L., & Munsterman, G. T. (2002). Are hung juries a problem? National Center for State Courts.