A Tucson police lieutenant was demoted after she took sexually explicit videos, and a provocative photo of herself wearing her police uniform shirt, and sent them to a subordinate officer with whom she was in a relationship, department officials said Monday.

Lt. Diana Lopez, a former public information officer for the Tucson Police Department, was reduced to the rank of sergeant following an investigation that began in last August. Anonymous letters sent to the department and the City Attorney's Office about Lopez prompted the probe, according to a departmental report made public Monday.

The internal affairs investigation found that Lopez sent photographs and videos using her personal cell phone to the subordinate officer, whose name was not released.

That officer then apparently shared the videos with other TPD officers, the report said. This happened from May 2011 through August 2011, the report said.

Lopez violated several department regulations, professional standards and a code of ethics, the police documents say.

"Lopez used extremely poor judgment in sending these images undermining her credibility as a commander. Her actions have negatively affected not only her reputation, but the reputation and mission of the Tucson Police Department," wrote Assistant Chief Kathleen Robinson.

Lopez is now a patrol sergeant in Operations Division South, said Sgt. Chris Widmer, a TPD spokesman.

Widmer said the investigation is ongoing. He would not elaborate.

No interviews were given Monday by Police Chief Roberto Villaseñor or police commanders about the findings.

Attorney Michael Piccarreta, who represents Lopez, said she is considering a civil lawsuit against the city, or appealing the demotion through the Civil Service Commission.

"The case raises constitutional issues when there is a lawful off-duty behavior, and a wrongdoer violates your trust and privacy rights without your permission or consent by making it public," Piccarreta said.

According to police documents:

• Lopez acknowledged that one video shows her kissing a person in a police locker room while she was on duty.

• Lopez said a sexually explicit video of herself was taken at her home while she was off-duty.

• Thirteen people "might have, or might have knowledge" of the videos and photographs. They were ordered to turn the material over to the department, but all said "they did not have the material in question." The videos and photo were not found during the internal affairs investigation, "but there is no doubt they exist."

• One officer told investigators that Lopez had shared sex videos with him, and as far as he knows, they were not taken on department property. He also said he forwarded the videos electronically to other officers, and personally showed video to a sergeant.

• Other officers saw the sex videos, including some clips that did not identify the woman.

• Capt. John Stamatopoulos had lunch with Capt. Clayton Kidd in August 2012 and Stamatopoulos revealed to Kidd "the secret about the tapes" that Stamatopoulos had kept to himself for 10 months.

• The investigation found Stamatopoulos failed to notify the department about the videos and photographs. He received a written reprimand.

• Kidd denied that he was aware of any graphic "sex videos" pertaining to Lopez. He said he heard there was some type of "Girls Gone Wild" video, including a number of female personnel on a trip to Las Vegas.

• Kidd was cleared of wrongdoing.

Contact reporter Carmen Duarte @azstarnet.com or 573-4104.