On police bias in Florida Highway Patrol speeding tickets, Tim Taylor reports:
"There is an enormous spike in those given tickets for being about 9 mph over the speed limit. ... In Florida, the fine for being 10 mph over the limit is substantially higher. ... the spike at 9 mph is higher for whites than for blacks and Hispanics. This suggests the likelihood that whites are more likely to catch a break from an officer and get the 9 mph ticket."
"Bias and discrimination doesn't always involve doing something negative. In the modern United States, my [Taylor's] suspicion is that some of the most prevalent and hardest-to-spot biases just involve not cutting someone an equal break, or not being quite as willing to offer an opportunity that would otherwise have been offered."
And: "[T]he majority of officers exhibit no bias, with the aggregate disparity in treatment explained by the behavior of a small minority of officers composing about 20% of the patrol force. We also explore how bias varies with officer-level characteristics, documenting that officers exhibit own-race preferences and that younger, female, and college-educated officers are less likely to be biased."
Link to the paper by Goncalves and Mello here.