Homeland Security CTO announces departure

The Department of Homeland Security's top technology official has departed after a nearly four-year tenure at the agency marked by a greater embrace of artificial intelligence capabilities. 

David Larrimore announced in a Friday LinkedIn post that April 25 was his last official day as the DHS chief technology officer, a role that he held since August 2021. 

“It has been an incredible ride and I was fortunate enough to be at the forefront of bringing AI to DHS in a big way,” Larrimore wrote. “I could not have done anything without the tireless efforts of my team and colleagues from around the Department that shared the same vision. I got to collaborate and work with some of the most talented and driven people I have ever met.”

The department has taken a leading role across federal agencies in embracing AI capabilities, with DHS issuing the first AI roadmap in response to former President Joe Biden’s October 2023 executive order on the safe and secure use of AI. President Donald Trump subsequently rescinded Biden’s order upon taking office and his administration issued new guidance earlier this month outlining how agencies should use AI.

The CTO position at DHS is now dual-hatted as the department’s chief AI officer, and Larrimore said that he led a team of roughly 150 employees and contractors in this combined role. He took on oversight of the department’s AI-related efforts after Eric Hysen — the former DHS chief information officer and chief AI officer — departed in January.

Among his initiatives while with the department, Larrimore helped to spearhead the creation of the DHS AI Corps, which was focused on hiring an initial cohort of 50 AI experts to help leverage emerging capabilities across the department’s operations. DHS first announced the effort in February 2024.

The AI Corps was modeled on the White House’s U.S. Digital Service, which has since been rebranded under the Trump administration as the U.S. DOGE Service after the Elon Musk-led Department of Government Efficiency. DHS — under the current leadership of Secretary Kristi Noem — is reportedly looking to cut the AI Corps, according to an article published earlier this month by Federal News Network. 

Larrimore also led the development and implementation of an AI powered chatbot — dubbed DHSChat — focused on helping the department’s roughly 19,000 personnel safely and securely use non-public data. The tool was launched last December and is designed to help employees with often rote tasks, such as drafting reports and summarizing information. 

Prior to joining DHS, Larrimore worked as a lead solution engineer at Salesforce. He also served as CTO at U.S. Immigration and Customs Enforcement between 2016 and 2019 and as a cloud strategist at the Department of Agriculture in 2016.