MINNEAPOLIS (WCCO) — Heroin deaths in Hennepin County declined slightly in 2014, but the drug is getting cheaper in the Twin Cities — and has one of the highest purity levels in the country.

The Hennepin County Sheriff’s office says there were 50 heroin deaths last year, compared to 56 in 2013 – the deadliest year for the drug on record. There were eight total in 2010.

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Two people died from overdoses in Hennepin County just last month.

The rise in heroin use is being attributed to the abuse of opiate-based prescription painkillers, like Vicodin and OxyContin.

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Authorities say once people have grown addicted and run out of these increasingly hard-to-obtain prescription drugs, they may turn to heroin.

The illegal drug is both very cheap and highly potent in the Twin Cities, and many overdose deaths are attributed to the user underestimating the strength of a typical dose.

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The sheriff’s office says they held “Heroin Town Hall Meetings” last year in Brooklyn Center, Hopkins, Maple Grove, Minneapolis, Minnetonka and Plymouth.