See how doctors deal with the dangers of perscribing pain medication in a special report on "American Morning" Wednesday 6 a.m. ET

Louisville, Kentucky (CNN) -- Detective Steve Watts is locking up another accused pain pill addict. But he's seen this suspect before.

She's back in handcuffs for the second time in less than a week. The charge this time, like it was just four days ago, is fraudulently obtaining prescription medication.

For Watts and the other detectives of the Louisville Police Department Prescription Drug Diversion Squad, it will be one of 500 to 600 arrests they make each year.

Even with arrests nearly every day, "We're just scratching the surface," according to Watts. The number of investigations the unit initiates is up 148 percent compared with a year ago.

It can be surprisingly easy to get prescription narcotics that are highly addictive, and they're highly profitable on the street.

But detectives in Louisville say most of the people they arrest aren't in it for the money. Instead, they get pills to support their own habit, and police say they have a variety of methods for feeding their addiction.

A former nurse will use her medical training to impersonate a doctor to call in fake prescriptions to a pharmacy and simply go in and pick up her drug of choice. Others use prescription pads stolen from physicians or "doctor shop" by getting legitimate prescriptions from multiple doctors who are unaware of what other drugs their patients are already taking.

Watts sees his job as giving those he arrests a wake-up call. "If I can make this the worst day of her life so that tomorrow she will seek treatment, then I've won," he said.

Kentucky is among the top states in the country for prescription pill abuse, according to the National Survey on Drug Use and Health.

"People think that, well, it's authorized by my doctor, we can pick it up at any of the local retailers on the corner, and that prescription abuse is not really a problem," Watts said.

The vast majority of those Watts and his fellow detectives arrest start their addiction with legitimate needs for pain medication from something such as a car accident. But then they can't stop.

That's what worries physicians such as Dr. David Greene.

"We know that narcotics are potentially addictive -- we don't know who might become addicted and who might not," he said.

Greene practices in eastern Kentucky, where he says prescription pill abuse is rampant.

"It's come to the point where there are few people who don't have someone in their family or know someone who's had problems with addiction, overdose or abuse," Greene said.

When patients come looking for a prescription for powerful pain medication, doctors like him are forced to determine whether the need is real or whether the patient might be an addict.

"There's no test for pain," Greene said. "The only thing we have to go on is what they tell us, and I generally believe my patients. But most people who are going to lie to you are much better liars than you are at detecting."

One of those patients who Greene says fooled him was a 79-year-old grandmother who was selling her pills out of her nursing home.

If the patient is an addict, doctors refuse them at their own peril. In December, a man came into Dr. Dennis Sandlin's rural clinic in Perry County, Kentucky, looking for a prescription. Sandlin demanded that he take a urinalysis test to check for drugs in his system. Later that morning, the patient returned and shot and killed Sandlin.

"My dad was writing in a chart at the nurse's station. Someone heard my dad say, 'You don't want to do this. I take care of a lot of elderly people.' And he said, 'well you didn't help me' and that's when he shot him," Sandlin's daughter Danielle said.

Danielle is now working to raise awareness of the dilemma doctors face in prescribing pain medication. Her father, she said, was rigorous about prescribing pain medication.

"He would drug test the pope if he came in asking for something."

Greene has encountered intimidating patients in his clinic as well. "Physical violence is a real fear. We have people who come in who are threatening and abusive," he said.

After having one patient impersonate him, Greene no longer calls in controlled substances prescriptions into local pharmacies.

Some doctors, fearing either physical violence or contributing to addiction, have stopped prescribing pain medication altogether. That puts doctors such as Greene, who do prescribe, in a difficult position.

"No matter what you do, you're going to have an unintended consequence," Greene said. "If you refuse to prescribe, you'll end up with people suffering. And if you do prescribe, you'll find patients diverting them, selling them, using them for recreation."

The solutions, police and doctors say, range from electronic prescriptions that would be difficult to forge to a national prescription database that would allow doctors to see what other drugs a pill-seeking patient is already taking.

Danielle Sandlin is pushing for some kind of reform in the wake of her father's death.