A doctor and his wife charged with operating a "pill mill" that prosecutors said caused the overdose deaths of at least four patients will remain in jail because they are a flight risk, a federal magistrate ruled Friday.

Dr. Stephen J. Schneider and his wife, nurse Linda K. Schneider, pleaded not guilty in U.S. District Court to counts including conspiracy, unlawful distribution of a controlled substance, health care fraud, illegal monetary transactions and money laundering.

The Schneiders, who were arrested Wednesday, are not charged with killing any patients.

The doctor's court-appointed attorney, Jay Greeno, told the judge his client "still has patients out there that still need him."

But U.S. Magistrate Judge Donald Bostwick ruled he posed a danger to the community, because even if he was ordered to not practice medicine there was no way the court could police that stipulation.

"I do not see conditions I can impose that would adequately protect the community," Bostwick said.

The court-appointed attorney for Schneider's wife, John Rapp, said at her later hearing that with her husband in jail, she could not prescribe medication and posed no danger.

"We are disappointed with the decision," Rapp said after the hearing. "We have to live with it." He declined to discuss the charges, saying he was not yet familiar with her case.

Prosecutors contend the couple pose a danger to the community by continuing to practice medicine and prescribe drugs. The Schneiders' clinic had been under investigation for years and was raided by federal authorities in September 2005. Prosecutors say the pair continued their fraud despite knowing the government was investigating them.

According to the indictment, 56 of the doctor's patients have died from accidental prescription drug overdoses in the past five years. However, the indictment alleges that only four of the deaths were directly caused by drugs prescribed by Schneider's clinic in Haysville, south of Wichita.

Linda Schneider's sister, Pat Hatcher, told reporters after the hearing that five doctors in that clinic treat patients. Insurance companies often put Schneider's name on patient records, Hatcher said, adding that some of the patients named in the indictment were not even his patients.

"I don't think the doctor is guilty," she said. "I don't think the doctor would hurt a flea."