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Drug trends across King County: Crime lab data

Here we examine trends in crime lab cases, reflecting drugs seized by state and local law enforcement in King County (cases from federal and other multi-county agencies are not included due to lack of county specificity). Three categories of drugs are presented:

Counts represent the number of cases in which a given drug was found, regardless of the number and amount of substances tested. See our new and emerging drugs in crime lab evidence page for an explanation of why crime lab cases dropped in 2021.

Counts of cases over time

Data source: Forensic Laboratory Services Bureau, Washington State Patrol. 2021 counts and onward are impacted by the 2/25/2021 Washington State v Blake decision.
Data source: Forensic Laboratory Services Bureau, Washington State Patrol. 2021 counts and onward are impacted by the 2/25/2021 Washington State v Blake decision.
Data source: Forensic Laboratory Services Bureau, Washington State Patrol. Phenethylamines here excludes methamphetamine and amphetamine. 2021 counts and onward are impacted by the 2/25/2021 Washington State v Blake decision.

As a share of all drug cases

While the above charts looked at counts of drug cases, below we focus on what proportion of all drug cases involved the same drugs of interest. This helps us understand how prominent the drug has been in law enforcement case loads, which of course reflects not only prominence among drug users but also prominence among law enforcement and among distributors and dealers. For example, the proportion of drug cases involving cannabis has fallen in recent years due to de-emphasis among local law enforcement and then legalization of recreational marijuana. The share of cases involving cocaine has fallen from nearly half to around 1 in 6. Heroin and methamphetamine, on the other hand, became more and more prominent in the county in the 2010s. The increase in heroin drug cases was consistent with an increase in King County deaths attributed to heroin as well. Since 2017, however, heroin has decreased in prominence with the shift towards fentanyls.

Again, to highlight less common drugs and better see their growth, turn off the most common drug(s) in a chart by clicking on the drug name(s) in the legend.

Data source: Forensic Laboratory Services Bureau, Washington State Patrol
Data source: Forensic Laboratory Services Bureau, Washington State Patrol
Data source: Forensic Laboratory Services Bureau, Washington State Patrol. Phenethylamines here excludes methamphetamine and amphetamine.

To King County drug deaths (no longer updated)

To King County opiate treatment (no longer updated)