When a civil wrong is committed, the penalty is approximately equal to the gains resulting from the violation; in criminal cases, the penalty is much greater than the gains to the violator. In addition, standards of proof differ: in civil actions, the standard of proof is preponderance of the evidence, while in criminal cases it is the reasonable doubt standard. The study assumes Friedmann-Savage utility functions, with risk aversion for small gains or losses and risk seeking for larger gains. It is argued that criminals are simply those individuals who realize larger gains from criminal activity than would noncriminals. Behavior is then analyzed using the Polinsky and Shavell mathematical model but with allowance made for risk-seeking and risk-averting behavior. Application of the model demonstrates that probabilities of conviction for crimes should be lower and that penalties should be larger than would be the case for a civil wrong. The model also demonstrates that low probabilities of conviction are equivalent to high standards of proof. Only conditionally deterred crimes are considered using the model. Thirteen footnotes are provided. (Author summary modified)