WAUKESHA COUNTY - Heroin is hitting Milwaukee's affluent suburbs hard.

In the first six months of this year, more people died from heroin in Waukesha County than in any other entire year.

Now, top cops there issuing a strong warning to parents.

The TODAY'S TMJ4 I-Team had unprecedented access to the Waukesha County Metro Drug Enforcement Unit. J.B. is an undercover agent there.

"This guy could be dealing to my little brother, to a kid out on the street, to anyone," J.B. said.

Metro officers have advice for suburban parents who think their kids could never get hooked on heroin.

"Talk to your kids about heroin. Talk to your kids about the effects of it. A little knowledge goes a long way," one officer said.

Village of Pewaukee Police Chief Ed Baumann says parents need to follow their instincts if something seems wrong.

"You can't try to work out a lot of things and sit down and wonder if my kid is involved. I'm going to sit down and say he or she is. If I'm wrong it's one little mistake I've made," Baumann said.

If you're right, you may have saved your child's life.

"The alternative is horrible. It's grief counselors up at the school., it's you picking out a coffin for your kid, for your kid who's in his teens or twenties," Baumann said.

"It took over my whole life. Everything I ever had was gone; family, friends," Greg, a former user, said.

There are a few specific things that experts say parents should watch out for: keep track of how your kids spend their money, monitor their schedules and friends, and be aware of their eating or sleeping patterns drastically changing.