As a result, "three strikes" proponents were forced to shift their explanation—the law deterred potential offenders. In certain instances, depending on which method the authors used, they did find a marginal deterrent effect.
But the effect was extremely small and cannot explain the significant overall decline in the crime rate.
For example, within California, counties that aggressively enforce the law "had no greater declines in crime than did counties that used it far more sparingly." See Contra Costa Times, Feb. One study found that crime dropped by 21.3 percent in the six most lenient "three strikes" counties, compared to a 12.7 percent drop in the toughest counties.
, reports the results of the most comprehensive study of "three strikes" to date.
The authors’ findings suggest that, prior to "three strikes," crime rates were declining already and, after "three strikes" they continued to decline at about the same rate, suggesting that whatever effect "three strikes" had, it was small at best.