it's not the tar; it's the fentanyl, stupid. (or, another AP asshat)

The AP misses the boat, again.
What they describe is, in fact, impossible. They are describing the effects of fentanyl, not heroin. Trust me, addicts would be a lot more excited about black tar heroin if the purity was ever 90%.Heroin does not magically disappear in post-mortem toxicology tests. Fentanyl, on the other hand, requires a specific and often excluded test.
Try again, fools.

AP IMPACT
Deadly, ultra-pure heroin arrives in US
WINFIELD, Mo. — Mexican drug smugglers are increasingly peddling a form of ultra-potent heroin that sells for as little as $10 a bag and is so pure it can kill unsuspecting users instantly, sometimes before they even remove the syringe from their veins. ....