Memphis police chief says officers had 'no proof' to pull Tyre Nichols over

• Memphis' police chief told CNN her department hasn't found proof Tyre Nichols drove recklessly.
• Nichols was beaten by Memphis police officers during a traffic stop on January 7.

Memphis Police Chief Cerelyn J. Davis told CNN Thursday morning that her department has not found proof of Tyre Nichols driving recklessly — the reason police officers used to pull him over on January 7.

"We've looked at cameras, we've looked at body-worn cameras, and even if something occurred prior to the stop, we've been unable to substantiate that at this time," Davis told CNN. "We have not been able to substantiate the reckless driving."

Nichols was stopped by Memphis police officers at a traffic light on January 7 and accused of reckless driving. During the traffic stop, the police officers beat Nichols, and he died in the hospital three days later, on January 10.

"We've taken a pretty extensive look to determine what the probable cause was, and we have not been able to substantiate that," Davis told CNN of the reckless driving claim. "It doesn't mean that something didn't happen, but there's no proof."

Five officers were charged with murder in connection to Nichols' death. Memphis police are expected to release the body-camera footage of the incident Friday evening.

Davis has warned that what the footage shows is "heinous" and "inhumane" and could lead to public protests.