Crime Index Data for Legal Marijuana States 

Population and Rate of Crime per 100,000 People
The crime "Index" is made up of the total number of violent and property crimes.  Since most crime is property related the crime index gives more weight to property crime.  Per capita statistics are based on shifts in population. Example California has seen a population increase of 3 million and Washington has added 1 million since 2008, so total crimes may have increased due to a larger population.  

COLORADO  
CRIME INDEX STATISTICS
(Crime per 100,000 residents, the lower number is better)
Year | Population | Index
2008 - 4,935,213  - 3,206.3   
2009 - 5,024,748  - 3,009.5  
2010 - 5,047,692  - 2,998.2
2011 - 5,116,302  - 2,909.7 
2012 - 5,189,458  - 2,992.7 
2013 - 5,272,086  - 2,960.4  *LEGALIZATION
2014 - 5,355,588  - 2,843.3 
2015 - 5,448,819  -  2,962.0 
2016 - 5,530,105  - 3,095.3 
2017 - 5,615,902  - 3,079.4 
2018 - 5,695,564  - 3,068.8 (4.3% lower than 2008)
WASHINGTON
CRIME INDEX STATISTICS
(lower number is better)
Year   | Population |  Index  
2008  - 6,566,073   - 4,106.3  
2009  - 6,664,195   - 4,015.9  
2010  - 6,742,950   - 4,012.6 
2011  - 6,823,267   - 3,874.4 
2012  - 6,895,318   - 3,987.2 
2013  - 6,973,742   - 4,005.9 * LEGALIZATION
2014  - 7,063,166   - 3,984.7 
2015  - 7,160,290   - 3,770.5 
2016  - 7,288,000   - 3,796.3 
2017  - 7,425,432   - 3,470.4 
2018  - 7,535,591   - 3,257.7 (20.67% lower than 2008)
OREGON
CRIME INDEX STATISTICS
 (lower number is better)
Year  Population  Index  
2008  - 3,782,991 - 3,565.6 
2009  - 3,825,657 - 3,260.9 
2010  - 3,838,332 - 3,290.7 
2011  - 3,868,229 - 3,399.8 
2012  - 3,899,801 - 3,488.7 
2013  - 3,928,068 - 3,427.1 
2014  - 3,971,202 - 3,360.1 
2015  - 4,024,634 - 3,240.9 *LEGALIZATION
2016  - 4,093,465 - 3,229.0 
2017  - 4,146,592 - 3,235.2 
2018  - 4,190,713 - 3,179.5 (10.77 lower than 2008)
CALIFORNIA
CRIME INDEX STATISTICS
 (lower number is better)

Year | Population | Index 
2008 - 36,580,371 - 3,460.7 
2009 - 36,961,664 - 3,204.3 
2010 - 37,338,198 - 3,069.5 
2011 - 37,683,933 - 2,995.4 
2012 - 37,999,878 - 3,185.3 
2013 - 38,431,393 - 3,053.8 
2014 - 38,792,291 - 2,838.1
2015 - 38,993,940 - 3,056.4 
2016 - 39,296,476 - 2,994.8 
2017 - 39,399,349 - 2,958.6 *Legalized
​2018 - 39,557,045 - 2,827.8 ​(18.29% lower than 2008)

NEVADA
CRIME INDEX STATISTICS
 (lower number is better)

Year | Population | Index 
2008  - 2,615,772 - 4,159.0   
2009  - 2,643,085 - 3,768.9  
2010  - 2,704,283 - 3,436.5 
2011  - 2,720,028 - 3,144.4 
2012  - 2,754,354 - 3,422.7 
2013  - 2,791,494 - 3,441.4 
2014  - 2,838,281 - 3,263.1 
2015  - 2,883,758 - 3,372.5 
2016  - 2,940,058 - 3,264.7 
2017  - 2,972,405 - 3,195.5 *LEGALIZED
2018  - 3,034,392 - 2,979.3  (28.37% lower than 2008)

DC
CRIME INDEX STATISTICS
 (lower number is better)

Year | Population | # Crimes | Index 
2008 -  590,074 - 38,720 - 6,561.9 
2009 -  599,657 - 36,584 - 6,100.8 
2010 -  604,912 - 36,828 - 6,088.2 
2011 -  619,020 - 37,087 - 5,991.3 
2012 -  633,427 - 38,623 - 6,097.5 
2013 -  649,111 - 39,512 - 6,087.1 
2014 -  659,836 - 42,346 - 6,417.7 
2015 -  670,377 - 39,982 - 5,964.1 *LEGALIZED
2016 -  684,336 - 40,613 - 5,934.7 
2017 -  695,691 - 36,712 - 5,277.0 
2018 -  702,455 - 37,720 - 5,369.7 (Total violent crimes have decreased 2.58% since 2008. With a 19% population increase and decline in total crime, the crime index is 98% lower than 2008)