A manager for a prominent private security firm that provides bodyguards to Silicon Valley executives received a concealed-gun permit from the Santa Clara County Sheriff’s Office months after he made a $45,000 contribution to an independent committee supporting Sheriff Laurie Smith’s 2018 re-election, newly disclosed records show.

The campaign contribution is one focus of an investigation by the Santa Clara County district attorney’s office into whether the sheriff gave out the coveted gun permits in exchange for campaign support, sources familiar with the probe have told The Chronicle.

Prosecutors have served at least three search warrants in the investigation, raiding the sheriff’s San Jose headquarters Aug. 2 and seizing evidence as well from two of the sheriff’s higher-ranking supervisors, said the sources, who spoke on the condition that they not be identified and in accordance with The Chronicle’s policy on using such sources.

A personal attorney for Smith, who was voted into office in 1998, said she has never exchanged campaign contributions for gun permits.

Among those who have been contacted by investigators is the security company AS Solution of Bellevue, Wash., which has said it is cooperating with prosecutors. The company has provided executive protection to Facebook CEO Mark Zuckerberg, Google executives and other CEOs in Silicon Valley.

According to documents obtained Thursday by The Chronicle under a public records request, Martin Nielsen, a manager for AS Solution, received a concealed-gun permit on March 26. That was a little more than five months after he gave $45,000 to the Santa Clara County Public Safety Alliance, an independent expenditure committee that supported Smith’s re-election.

Nielsen, who has not responded to requests for comment, has no other record of past political contributions in Santa Clara County.

The records obtained by The Chronicle show that another executive protection agent for AS Solution also received a concealed-weapon license on March 26. She has since started working for Facebook, which declined comment for this story Friday.

The Chronicle identified nine individuals who appeared to have directly contributed to Smith’s campaign in 2018, then afterward received a concealed-gun permit. The contributors gave between $100 and $1,000. Some were regular political donors in Santa Clara County, while others had no history of financially backing local campaigns or politicians.

Prosecutors have released no evidence connecting Nielsen’s contribution to the approval of the gun licenses, and the search warrants are sealed.

A spokesman for the Sheriff’s Office did not immediately respond Thursday to telephone and email messages seeking comment.

The district attorney’s office declined to comment Thursday beyond an earlier statement that confirmed that investigators conducted the August raid of the Sheriff’s Office.

Demand for security has been high among Silicon Valley companies and executives, particularly since April 2018, when a YouTube video creator stormed the company’s San Bruno headquarters and shot three people before taking her own life.

Many private guards are retired police officers who may carry hidden guns in California. Those who are not retired officers must apply for permits from their home city or county. The permits generally must be renewed after two years.

Over the past two years, the Santa Clara County Sheriff’s Office has issued 76 concealed-weapon licenses, the new records show.

State law requires applicants to complete a training course, be of “good moral character” and show “good cause” for why they need a concealed weapon. But county and city law enforcement agencies have broad discretion in determining who meets those criteria.

AS Solution released a statement after the raid of the Sheriff’s Office saying it is “cooperating fully with the Santa Clara County district attorney’s office, and we have launched our own internal investigation into this matter.

“AS Solution employees are required to obey the laws, rules and regulations of all countries where we conduct business, and any allegations of improper conduct by employees are treated very seriously,” the statement said. “We will take appropriate action based on the outcome of our investigation.”

Josh Koehn, Matthias Gafni and Joaquin Palomino are San Francisco Chronicle staff writers. Email: josh.koehn@sfchronicle.com, matthias.gafni@sfchronicle.com, jpalomino@sfchronicle.com Twitter: @Josh_Koehn, @mgafni, @JoaquinPalomino