A 14-year-old boy accused of dealing heroin was arrested Wednesday night after Dallas police raided his home and found the drug — as well as several handguns, a rifle and hundreds of rounds of ammunition.

Police say the boy sold heroin from his South Dallas home while an 8-year-old relative acted as his lookout. The teenager also instructed an undercover officer on how to mix the drug with an over-the-counter sleep aid to make “cheese.”

"It’s hard to say at this particular time, but with the amount of baggies, it appears as though this is something that's been going on for quite some time,” said Dallas Police Deputy Chief Julian Bernal, commander of the narcotics division.

After police got a tip about the home in the 500 block of Rayenell Avenue, they sent an undercover officer to buy heroin from the teen. Armed with that evidence, they got a search warrant and raided the home about 8 p.m. Wednesday.

Officers at first found only the boy’s parents, Mary and Pedro Gopar, inside the home. But the teenager soon arrived and was arrested. Police are investigating whom the weapons belonged to and whether the parents played any role in the operation.

The couple were taken into custody Wednesday night but released without charge. Officers arrested another of their sons, 27-year-old Abram Rodriguez, as he drove away from the home while the raid began. Police say they found a bag of heroin in the console of his pickup. The teen is not being identified because he is a juvenile.

One of the many disturbing facets of the case, police say, is that the 14-year-old instructed the undercover officer on how to make cheese with an ingredient he claimed was safer than Tylenol PM, which has often been mixed with heroin to make cheese.

This 14-year-old is telling people that if you mix it with Nytol, you’re not going to die,” Chief Bernal said. “We find that particularly disturbing, because the message is lost that it’s the heroin that's killing the children.”

At least 26 North Texas youths 18 and younger have died from cheese overdoses since 2005, according to an ongoing Dallas Morning News analysis.