"Though it is still too early to make a final judgment, RAND found that three strikes and truth-in-sentencing laws have had little significant impact on crime and arrest rates. According to the Uniform Crime Reports, states with neither a three strikes nor a truth-in-sentencing law had the lowest rates of index crimes, whereas index crime rates were highest in states with both types of get-tough laws."

Source

Turner, Susan, RAND Corporation Criminal Justice Program, Justice Research & Statistics Association, "Impact of Truth-in-Sentencing and Three Strikes Legislation on Crime" Crime and Justice Atlas 2000 (Washington, DC: US Dept. of Justice, June 2000), p. 10.
http://www.jrsa.org/programs/…