Crime will drop.
Take a look at the results from America's Prohibition #1. As you can clearly see, murder rose during times of prohibition and dropped afterwards.

(the re-emerging spike in the 2nd crime graph is Prohibition #2's effect)

http://www.newspeakdictionary.com/ct-prohibition.html
Euphoric Reviewed by Euphoric on . Mexico set to decriminalize! http://news.yahoo.com/s/nm/20060428/ts_nm/mexico_drugs_dc Mexico set to decriminalize pot and cocaine By Noel Randewich 28 minutes ago MEXICO CITY (Reuters) - Possessing marijuana, cocaine and even heroin will no longer be a crime in Mexico if the drugs are carried in small amounts for personal use, under legislation passed by the Mexican Congress. Rating: 5