3 current, former San Francisco cops charged with destroying evidence, taking gun from property room

San Francisco D.A. Chesa Boudin behind a sign saying "SFPD police line do not cross"
San Francisco Dist. Atty. Chesa Boudin at a news conference in 2020.
(Jeff Chiu / Associated Press)

Two San Francisco police officers and a retired officer were charged this week in two criminal cases involving drugs that were flushed down a hotel toilet instead of being collected as evidence and a submachine gun that went missing from police custody.

Officer Kevin Lyons was charged with two misdemeanor counts of destroying evidence, and Officer Kevin Sien was charged with one count. Retired Officer Mark Williams was charged with three felonies: unlawful possession of a machine gun, possession of a silencer and embezzlement, San Francisco Dist. Atty. Chesa Boudin said Tuesday. The officers surrendered to authorities later that day.

In July, Lyons and Sien responded to a call at the San Francisco Marriott Marquis after staffers found what they thought was methamphetamine, multiple credit cards and identification cards in the luggage of a guest who was locked out of their room for nonpayment, prosecutors said.


When Lyons and Sien arrived at the hotel, they told the workers it would take too long to catalog all the evidence.

The officers then shredded the credit cards and ID cards, while Lyons flushed the suspected drugs down a hotel toilet, authorities said. They were reported to internal affairs the next day.

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Lyons, a 21-year veteran of the San Francisco Police Department, and Sien, a five-year veteran, were both transferred to assignments without public contact, according to the department.

“The actions of these SFPD members violate the law and regrettably fall far short of our department’s shared values,” Police Chief Bill Scott said in a statement. “As sworn police officers, we have no higher obligation than to earn and maintain public trust, and we are disappointed that these incidents detract from the outstanding work done by our officers and non-sworn members every day.”

Sien’s attorney, Christopher Shea, said “there’s a lot of daylight between sloppy police work and criminal conduct.”

He accused Boudin of filing a criminal charge that he said could have been rectified as an administrative matter within the Police Department.


San Francisco Police Commissioner and defense attorney John Hamasaki, who is often critical of the Police Department, said that officers tend to cut corners or don’t respond to calls, and that the department resists implementing reforms and progressive policies.

“Part of my long concern with the department is that we’ve been going through years of reforms, we had the Department of Justice come in [2016]. I think we’ve made some progress as far as updating our policies, our training, but there’s this old school, old guard culture that exists in SFPD,” Hamasaki said.

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In a statement, the San Francisco Police Officers Assn., the union that represents the department’s rank and file, said Lyons and Sien are “presumed innocent until proven otherwise beyond a reasonable doubt.”

“We are familiar with the alleged incidents and believe that once all of the evidence is disclosed, the facts will show that these charges were not warranted,” union President Tracy McCray said in a statement.

Both men were cited and released.

In the other case, police in August were taking stock of MP5 submachine guns that were set to be destroyed when they noticed one missing. Internal affairs was notified and an investigation was launched, Scott said, and four days later, Williams contacted a lieutenant in the property control division and admitted he had the gun at his home in Napa.

Williams had retired and was working part-time with the department in August; he was fired from that position after the firearm was recovered, authorities said. An arrest warrant was issued this month.


“We take the possession of illegal weapons very seriously in San Francisco and those who have weapons unlawfully will be held accountable,” Boudin said in a statement. “Keeping these dangerous firearms off the streets is critical to the security of our community. Officer Williams breached the trust and safety of our community when he removed the machine gun from SFPD’s custody.”

Williams’ attorney, Anthony Brass, said the firearm that Williams took from the property room was part of a seizure and was in that room for many years.

“The weapons were also inoperable in that they lacked parts which were needed in order to make them capable of firing,” Brass said in an email. “Mr. Williams was an officer trained in special weapons by his department and his curiosity about this system led him to make poor decisions.”

Brass added that Williams returned the weapon as soon as it was reported missing.