SALT LAKE CITY >> The videotaped arrest of a Utah nurse who refused to allow blood to be drawn from an unconscious patient has raised questions about how far officers can go to collect evidence and has led to policy changes within the Salt Lake City Police Department.

Here are some of the legal issues involved:

WHAT HAPPENED?

Police body-camera video released Thursday shows Salt Lake City Detective Jeff Payne handcuffing nurse Alex Wubbels on July 26 after she refused to allow blood to be drawn from an unconscious patient after a car crash.

In the video, Wubbels, who works in the burn unit at Utah University Hospital, explains she’s protecting the patient’s rights and she can’t take the man’s blood unless he is under arrest, police have a warrant or the patient consents.

None of that applied, and the patient was not a suspect. Payne’s written report says he wanted the sample to show the victim did nothing wrong.

The dispute ended with Payne telling Wubbels: “We’re done, you’re under arrest.” He pulled Wubbels outside while she screams: “I’ve done nothing wrong!”

Wubbels is being praised for her actions to protect the patient, while Payne and another officer are on paid leave. Criminal and internal affairs investigations are underway.

LEGAL ISSUES AT PLAY?

A 2016 U.S. Supreme Court ruling says a blood sample can’t be taken without patient consent or a warrant. But in this case, the officer reportedly believed he had “implied consent” to take the patient’s blood.

Implied consent assumes that a person with a driver’s license has given approval for blood draws, alcohol breath screenings or other tests if there’s reason to believe the driver is under the influence.

Paul Cassell, a criminal law professor at the University of Utah’s S.J. Quinney College of Law, wrote in an opinion piece for The Salt Lake Tribune that state law doesn’t permit a blood draw in this situation — especially since the blood was being sought to prove the patient was not under the influence.

Wubbels’ attorney, Karra Porter, said the state’s implied-consent law “has no relevance in this case whatsoever under anyone’s interpretation. … The officer here admitted on the video and to another officer on the scene that he knew there was no probable cause for a warrant.”

MEDICAL PERSONNEL VS. POLICE

Charles Idelson, a spokesman for National Nurses United, said a nurse’s prime responsibility is to be a patient advocate and protect patients, especially when they can’t consent themselves.

Meanwhile, police are investigators and have to capture forensic evidence, which in the case of a blood draw, is decaying with every passing minute, said Ron Martinelli, a forensic criminologist and certified medical investigator.

“For the officer, the clock is ticking,” Martinelli said.

But even with those different objectives, police and medical professionals routinely cooperate and conflicts like the Utah case are infrequent, Martinelli said.

THE OFFICERS

A second officer who was put on leave Friday has not been formally identified, but officials have said they were reviewing the conduct of Payne’s boss, a lieutenant who reportedly called for Wubbels’ arrest if she kept interfering.

Wubbels, who was not charged with a crime, has said that Payne “bullied me to the utmost extreme.” Payne hasn’t returned messages left at publicly listed phone numbers.

The Salt Lake City police chief and mayor also apologized and changed department policies on blood draws. Police spokeswoman Christina Judd said the new policy does not allow for implied consent for any party and requires a warrant or consent.

Judd also said the agency has met with hospital administration to ensure it does not happen again and to repair relationships.