i don't dispute any of agantyr's excerpts from Color of Crime, might go through it later but i am interested in the evidence that suggests negligible racial bias.
A way to gauge this is by looking at the correlation between suspects and arrestees. The annual crime report from New York City as a case in point:
http://www.nyc.gov/html/nypd/downloads/pdf/analysis_and_planning/enforcement_report_year_end_2014.pdfMurder and Non-Negligent Manslaughter: Blacks are 59.8% of the suspects and 61.8% of the arrestees. Hispanics are 30.3% of the suspects and 31.8% of the arrestees.
Rape: Blacks are 49.3% of the suspects and 43.2% of the arrestees. Hispanics are 37.7% of the suspects and 45.8% of the arrestees.
Other Felony Sex Crimes: Blacks 45.9% of the suspects, 39.3% of the arrestees. Hispanics 30.9% of suspects, 41.4% of arrestees.
Robbery: Blacks 70.6% of suspects, 61.5% of arrestees. Hispanics 23.7% of suspects, 29.6% of arrestees.
Felonious Assault: Blacks are 55.3% of the suspects, 53.2% of the arrestees. Hispanics are 31.2% of suspects and 32.5% of arrestees.
Grand Larceny: Blacks are 60.7% of suspects, 49.2% of arrestees. Hispanics 24.6% of suspects, 28.6% of arrestees.
Shootings: Blacks are 75.8% of the suspects, 74.6% of the arrestees. Hispanics 21.8% of suspects, 22.9% of arrestees.
Misdemeanor Sex Crimes: Blacks 46.0% of suspects, 42.8% of arrestees. Hispanics 35.0% of suspects, 39.5% of arrestees.
Misdemeanor Assault and Related Offenses: Blacks 52.4% of suspects, 46.5% of arrestees. Hispanics 32.7% of suspects, 36.8% of arrestees.
Petit Larceny: Blacks 55.2% of suspects, 43.7% of arrestees. Hispanics 26.2% of suspects and 32.1% of arrestees.
Misdemeanor Criminal Mischief: Blacks 48.1% of suspects, 37.8% of arrestees. Hispanics 31.1% of suspects, 37.5% of arrestees.
Stop Question & Frisk Subjects and Violent Crime Suspects: Blacks 64.5% of suspects, 54.6% of stops. Hispanics 26.7% of suspects, 27.8% of stops.
As we can see there's overall acceptable correlation between suspect and arrestee figures, if anything blacks are arrested at a lower figure than they are pointed out as perpetrators by victims and witnesses.
The race/ethnicity of suspects is recorded based on the victim's description following their interaction, and the race/ethnicity of arrestees is a result of officer assessment. For there to be bias the victims would first have to lie about the perpetrators then police would have to arrest entirely innocent blacks while letting guilty whites go free, perhaps not even bothering to look for them. New York City juries are very racially mixed and will not convict without convincing evidence. Also, whites are only 51.5 percent of the NYPD, which is 15.6 percent black, 26.7 percent Hispanic, and 6.2 percent Asian.
We can also look at how numbers correlate from one city to another.
In New York City a black is 31 times more likely and a Hispanic 9 times more likely to be arrested for a violent crime than a white. A black is 77 times more likely than a white to be arrested for a lethal or non-lethal shooting and a hispanic 18 times more likely.
In Chicago a black was (in 2010, last year we have statistics from) 32 times more likely than a white to be arrested for murder, and a hispanic nine times more likely. A black was 38 times more likely than a white to be arrested for robbery, and a hispanic was 6 times more likely.
I think it is reasonable to assume that sometimes there is racial bias by police, due to the fact that blacks are many times more criminal on average. Today also because police are using computer algorithms to predict risk factors which shapes police strategy in where to patrol and whom to suspect.
But it is also reasonable to assume that sometimes police do not react on it due to fear of creating a media circus. I must again recommend Ann Coulter's book I linked above, it goes through many tragic cases of the media spinning 'racist cop stories', destroying the lives of regular police officers just doing their work.