Sentencing disparity is defined as "a form of unequal treatment that is often of unexplained cause and is at least incongruous, unfair and disadvantaging in consequence".
Colloquially, situations wherein some criminals receive lighter criminal sentences or are held to a lesser standard of personal accountability is referred to as a slap on the wrist. The verbified form of such unequal treatment may be termed wrist slap, and alternative forms such as wristslap and wrist-slap. As an adjective, such a justice system may be described as being two-tiered or hybrid, both usually with negative connotations. Lawyers who uphold such unfair principles within the legal system are sometimes designated with pejorative terms such as double standardist.
Instances wherein women or cases have been perceived as upholding a gender disparity in sentencing have at times been labelled with derogatory terms such as pussy pass
It is important to distinguish disparity from differences that arise due to legitimate use of discretion in the application of the law and those differences that arise due to discrimination or other, unexplained, causes unrelated to the issues found in the specific criminal case. There is evidence that some U.S. federal judges give much longer prison sentences for similar offenses than other judges do.
This is a major problem because two judges could be faced with a similar case and one could order a very harsh sentence while another would give a much lesser sentence. A 2006 study by Crow and Bales gives evidence of sentencing disparity. The Florida Department of Corrections gave statistics of those prisoners who received probation or community control in the period 1990–1999. Prisoners were categorized as Blacks and Hispanics or Whites/Non-Hispanics. The study found that the Blacks and Hispanics received more intense and harsher penalties than the White/Non-Hispanic group.
A 2001 University of Georgia study found substantial disparity in criminal sentencing men and women received "after controlling for extensive criminological, demographic, and socioeconomic variables". The study found that "blacks and males are... less likely to get no prison term when that option is available; less likely to receive downward departures [from the guidelines]; and more likely to receive upward adjustments and, conditioned on having a downward departure, receive smaller reductions than whites and females".
In 2012 Sonja B. Starr from University of Michigan Law School found that "men receive 63% longer sentences on average than women do," and "[w]omen are…twice as likely to avoid incarceration if convicted."