Now it's up to the jury.

The evidence phase of the trial of Dr. Shakeel Kahn and his brother Nabeel Kahn -- accused of running a multi-state prescription drug conspiracy -- concluded Wednesday morning after closing arguments and jury instructions from U.S. District Court Judge Alan Johnson.

The federal government charged Shakeel Kahn with conspiracy to distribute controlled substances including oxycodone outside the standard of care resulting in death, operating a continuing criminal enterprise, having a firearm during a drug crime, money laundering, and using a telephone for a criminal purpose.

If convicted on all counts, Shakeel Kahn faces at least 45 years imprisonment.

If Nabeel Kahn [sometimes spelled Khan] is convicted of the charges against him -- conspiracy to distribute oxycodone and other drugs outside the standard of care and resulting in death, and brandishing a firearm in furtherance of a drug trafficking crime -- he faces at least 27 years imprisonment.

While Shakeel Kahn took the stand in his own defense Monday and his attorney Beau Brindley vigorously defended him in his closing argument Tuesday, Nabeel Kahn didn't testify.

His silence, which the jury cannot infer as guilt, was only slightly more quiet than the prosecution's case against him, his attorney Sean Bennett told the jury during the closing argument Wednesday.

"There's nothing there," Bennett said.

Khakeel hired Nabeel as an office manager and over time performed basic tests of vital signs such as noting weight and blood pressure, and giving prescriptions signed by Shakeel to patients, Bennett said.

Nabeel also liked to openly carry a pistol, which is legal in Arizona, he said. Nabeel once did pull it on an unruly patient in Shakeel Kahn's office in Fort Mohave, Ariz., and the matter was solved by the police and had nothing to do with the alleged drug conspiracy, he added.

A former patient and addict testified that he saw Nabeel Kahn watch an episode of the television show "20/20" which discussed the street value of certain drugs, but watching a television show is hardly evidence of a drug conspiracy, he added.

The charges against him cannot be proven "beyond a reasonable doubt" -- the standard that must be met for conviction -- and the government hasn't come close, Bennett said.

The federal government has been fighting the opioid epidemic, but that was no reason to charge Nabeel Kahn who is fighting for his freedom, he said. "They overreached."

Nabeel Kahn has maintained his innocence and did not enter a plea agreement like three other defendants who testified for the government, he said.

The lack of evidence in his case should be a warning to the jurors and the public, Bennett said. "If he can be brought in, anybody can be brought in."

Assistant U.S. Attorney Stephanie Sprecher finished the second part of her closing argument with time left over when she spoke Tuesday.

The prosecution's point has been to stop a "greedy opportunist," Sprecher said.

Contrary to the defense's characterization of the case as government overreach, she said the case started with a request from the Wyoming Board of Pharmacy to investigate what they perceived as Shakeel Kahn prescribing certain medicines beyond the usual standard of care.

Federal investigators looked at 25,000 prescriptions, thousands of documents, audio recordings and other evidence, Sprecher said. "The government didn't have to come up with anything; it was all there."

She referred to the patient records he "falsified" to justify the "crazy high" prescriptions before presenting them to the Arizona Board of Medicine earlier in the decade, she said. "He had to make them look legitimate, so he lied."

Kahn and his wife Lyn were looking for people who fit "the type" of patients who were young and low-income and could become addicted, repeatedly come back and have to sell their pills to support their habits, Sprecher said.

The defense criticized patients who lied to Kahn and when they were on the witness stand, she said.

But their lies were part of the conspiracy when they filled out documents he had including those that said they would take their medicines as prescribed and not sell them, and not call him a drug dealer or otherwise face legal and financial consequences, Sprecher said.

Those patients were examined on their first and second visits, kept lying about their conditions until they became comfortable with each other and needed to make fewer and fewer visits yet still receive prescriptions, she said.

At one point, investigators sent an undercover agent to visit Kahn and become a patient, Sprecher said.

On the first visit, the agent brought medical records documenting his pain, and was prescribed Percocet but no other recommendations to treat pain. On a subsequent visit, the agent received another prescription, and Kahn told him he'd prescribe more, but pharmacies might get suspicious, Sprecher said.

Nabeel Kahn, she added, was his business partner and involved in the conspiracy.

Before urging the jury to convict Shakeel and Nabeel Kahn, Sprecher said, "all he was doing was selling prescriptions for profit."