This paper capitalizes on information about firearm use available in a standard sentencing guideline worksheet to study who is ultimately convicted with a mandatory minimum firearm penalty in the state of Maryland. Findings show that the mandatory firearm penalty is applied in only 37 percent of all eligible cases, and it is associated with an additional 41 months of prison time. The penalty is not applied randomly, but appears to be part of an organized effort to punish more serious offenders convicted of more serious offenses. Race and gender are also significant predictors of being convicted under this penalty. It is possible that race and gender are only proxies for other unobserved characteristics, but this finding serves as an upper bound on the size of the gender and race effect in prosecutorial discretion, and demonstrates the potential for disparity in the charge bargaining stage of the sentencing process. (Published Abstract) References