Editor’s Note: This is the third of a three-part series about TBI Director Mark Gwyn’s views of crime in Tennessee.Surpassing even meth in potency and lethality, Tennessee Bureau of Investigation Director Mark Gwyn says heroin is a major concern given the number of overdoses being attributed the laced versions of the drug.“We had more overdose deaths in Tennessee than deaths due to traffic accidents,” Gwyn told McMinnville Noon Rotary Club members last week. “With meth going on, we didn’t pay as much attention to it.”Gwyn said the rise of heroin, a drug that was a niche drug during the late 1960s and ’70s, has accompanied the arrival of the Mexican drug cartel here, which replaced the Asian-dominated heroin trade. With the change came a drastic reduction in price given the number of people who are addicted to opioid pain killers.