CINCINNATI - Drug dealers are feeling the heat from the federal and police crackdown on selling heroin, fentanyl and deadly carfentanil.

Some are so afraid of harsher federal penalties they're refusing to sell the drugs, according to DEA informants.

"I know on at least one or two occasions when we’ve attempted to buy heroin, they said, ‘No, I’m not messing with that. They’re putting murder charges on people for that,' " said DEA Agent Tim Reagan.

"So, that’s a good sign."

Ohio penalties for selling drugs that harm the buyer range from two to 10 years in prison. Federal penalties can range from 20 years to life.

"I think if you’re selling heroin out there or what you think is heroin, you’re going to think twice about 20 to life if you’re selling $40 worth," said Lt. Tom Fallon of the Hamilton County Heroin Task Force.

RELATED: Feds announce groundbreaking federal carfentanil indictments in Cincinnati

The arrest of an Elmwood Place couple is being handled in the federal judicial system, and the word is spreading fast. With Phillip Watkins and Jeannetta Crawford behind bars accused of selling carfentanil, the next step for the DEA is finding out who their supplier is.

"They’re high enough up to definitely obtain it and distribute it. Our next step is looking at their phone records," Reagan said. "Hopefully they’ll cooperate in the future and we will be able to work up the ladder,"

They're also tracking how it gets into the country.

"We believe it’s being manufactured in China, sent to Mexico and then smuggled through the traditional routes that the cartels and drug traffickers already use," Reagan said. "So, from China, Mexico, up across the border, it could stay in Phoenix, it could stay in LA, it could stay in El Paso and slowly work its way to us."

Reagan said they’re pulling out all the stops to get to anyone else selling carfentanil off the streets.

"We’re looking for evidence that we can pull fingerprints off of, DNA off of, we’re going through cell records. We’re talking to witnesses," he said.

The Watkins/Crawford case came down to a user leading police right to them. But Newtown police Chief Tom Synan of the Hamilton County Heroin Task Force says getting users to talk isn’t easy.

"We’re talking about people who are suffering from this addiction. They don’t want to cut off their supply. They’re dealing with physical aspects of withdrawal," Synan said.

Synan says there’s not a standard technique to get someone to flip.

"It’s just one person talking to another, kind of explaining the situation and the consequences from all ends," he said.

Fallon says the arrests started with a drug bust in Springfield Township and required a huge amount of cooperation from law enforcers.

"Springfield Township Police, the Hamilton County Heroin Task Force, Cincinnati Police District 4 Violent Crimes Squad and their SWAT team and then DEA," he said.

Fallon said that’s the sort of cooperation police need to send a clear message and get results.

RELATED: See WCPO's special heroin coverage on our "Heroin in the Tri-State" page.