Research suggests that police practices, such as racial profiling, over-policing in areas populated by minorities and in-group bias may result in disproportionately high numbers of racial minorities among crime suspects. Research also suggests that there may be possible discrimination by the judicial system, which contributes to a higher number of convictions for racial minorities. A 2012 study found that "(i) juries formed from all-white jury pools convict black defendants significantly (16 percentage points) more often than white defendants, and (ii) this gap in conviction rates is entirely eliminated when the jury pool includes at least one black member." Research has found evidence of in-group bias, where "black (white) juveniles who are randomly assigned to black (white) judges are more likely to get incarcerated (as opposed to being placed on probation), and they receive longer sentences." In-group bias has also been observed when it comes to traffic citations, as black and white cops are more likely to cite out-groups.