louis, dea special agent jim shroba says the cartel devised a marketing plan to boost heroin production. >> they brought in better k chemi chemists. a better refinement process. they wanted to open up the market to individuals whose idea of heroin was the sir ring. they made it so pure, they gave new users, suburban users in this region the opportunity to snort it and get them hooked. >> reporter: in some cases, heroin sold on the street, once only 6% pure is now a staggering 90% pure. and the st. louis suburb where juan grew up, the death toll is alarming. >> in the st. charles county area, 2004, there was four overdose deaths. in 2013, there were 26. it's highly addictive. >> reporter: so many have died, juan decided to tour schools to warn young people. that community outreach led him to meet gee. her batter's battle touched him. they became family. nicky went through three years of rehab. she wasn college on the path to recovery, but it was a struggle. >> this is not your child anymore. physically, it looks like them, but the inside is not them anymore. that is someone who is contro