On busy Old Bridge Road in Woodbridge, a caravan of marked and unmarked police vehicles streamed into the Lake Ridge Executive Park office complex Tuesday afternoon. A large group of uniformed officers and masked undercover detectives stepped urgently into Building 2050, surprising a few pedestrians outside, and then entered the Neurological Center of Northern Virginia and arrested a doctor for allegedly putting pain pills onto the Prince William County streets.

The doctor, Samad Oraee, 53, of McLean, was released on bond later Tuesday and did not respond to requests for comment Wednesday. He previously achieved notoriety by losing a medical malpractice suit in the death of a patient in 2003 and then setting a legal precedent in Virginia for how doctors can be held liable for failing to read test results ordered by other doctors.

Tuesday’s raid was the latest phase of the Prince William drug task force’s Operation Dragon Slayer, which has tried to stem the tide of both illegal prescription pills and heroin in Northern Virginia. The detectives first targeted pain pills last fall after learning that the pills had become so expensive and difficult to find that users were turning to heroin.

After arresting about 40 alleged street-level dealers of heroin or pain pills in November, the operation tried a new approach in its second round of raids last month: offering 53 arrested drug dealers the opportunity to go straight to drug treatment, after booking, with drug counselors standing by to handle any takers. Six defendants accepted the offer, county officials said.

Next, the task force turned its focus to the source of prescription pain pills, often thought to be doctors who are willing to write unnecessary prescriptions or prescribe far more pills than needed so that the excess can be sold on the street. Detectives said dealers often sell pills for $1 per milligram, so that an 80-milligram oxycodone pill can cost $80. That cost, drug users said, played a part in driving them to heroin.

Oraee was charged with two counts of prescription fraud, and police said he wrote prescriptions for pain medications without properly performing necessary medical exams. The Web site for the Neurological Center of Northern Virginia describes Oraee, a neurologist, as “a highly saught doctor of Neurology and Pain Management with more than 23 years of experience treating patients with neurological issues and pain management.”

Sgt. Matt McCauley of the Prince William-Manassas City-Manassas Park Narcotics Task Force said he could not discuss the Oraee case. But he said doctors were being targeted because “these pharmaceuticals don’t hit the street in volume unless they’re prescribed by the doctors. It’s only one piece of the problem, but it’s a big piece.”

McCauley said people who approach doctors either fake ailments or get more medication than they need, and doctors who write such prescriptions “contribute to the general narcotics trade out on the street, which then leads to the heroin problem.”

In 2004, a Fairfax County jury ordered Oraee and another doctor, rheumatologist Mert T. Kivanc of Falls Church, to pay a Woodbridge family $2.5 million for medical malpractice in the death of Sherry Breeding, 52. The amount was reduced by state damages caps to $1.65 million. Breeding had gone to Potomac Hospital in Woodbridge in 2003, where Oraee determined that she had suffered a stroke and referred her to Kivanc. Kivanc ordered blood tests that showed that Breeding had a blood-clotting disorder, but testimony showed that Oraee did not consult the tests and prescribe clotting medication. Breeding suffered another stroke and died.

Oraee appealed, claiming that he had not ordered the medical tests and so had immunity from a medical malpractice claim. In 2005, the Virginia Supreme Court ruled in Oraee v. Breeding that physicians did not have such immunity.