No charges have been filed against the adjunct USC professor who was detained in connection with Monday's false reports of an active shooter at Fertitta Hall, according to a spokesperson for the Los Angeles Police Department.

The LAPD released the professor after the investigation concluded, finding no evidence that a crime had occurred. David Carlisle, assistant chief of the USC Department of Public Safety, said the professor has been put on 72-hour evaluation. It is up to USC to conduct an internal administrative investigation of the incident, the LAPD said.

As of Tuesday afternoon, USC's communications office had not responded to a request for comment.

The LAPD detained the professor Monday afternoon after she allegedly reported the presence of an active shooter on campus.  The department said the professor was questioned while in police custody.

Reports of a potential active shooter led campus police to urge people to "shelter in place."

The LAPD confirmed that there was no shooting after responding to a call at 12:17 p.m. about gunfire near Fertitta Hall.

DPS instructed students, faculty and staff to take shelter and avoid Fertitta Hall, where the reports originated. The LAPD subsequently conducted searches of the entire building.

Steven Goldfarb of the USC Office of Fire Safety and Emergency Planning said, "From an emergency planning perspective, the response was very quick and very coordinated." He urged students to sign up for the TrojansAlert emergency notification system and check the Active Shooter page on USC's website for more information.

Sophomore Brittany Hoang, who works in Fertitta Hall at the Marshall advising office, said she saw police walk onto the second floor of her office with guns.

"Police were yelling for everyone to evacuate," Hoang said. "People were running out of the courtyard, so I ran out the back of the building."

Campus activities returned to normal at 1:04 p.m. when the LAPD confirmed there was no evidence of a shooting and there were no injuries involved.

"We can confirm there's been no shooting on USC campus," the LAPD said on Twitter.

This story was updated on 10/3/17 at 5:23 p.m. with information regarding the status of the adjunct USC professor. The headline was also updated.

This story was updated on 10/2/17 at 4:11 p.m. with information regarding the questioning of the adjunct USC professor. The headline was also updated.

Adam Askenaizer, Morgan Stephens and Sebastian Vega contributed to this report.