Southfield Capital portfolio company Protos Security has acquired AT-RISK International, the firms announced April 27, 2026.

Financial terms were not disclosed.

AT-RISK International, founded in 2013 and headquartered in Washington D.C., provides executive and general protective services, risk consulting, investigations, threat assessments, and global risk monitoring.

Its client base includes enterprises and high-net-worth individuals.

Protos Security, established in 2006, is a tech-enabled managed security services provider in North America.

Its offerings include physical guarding, off-duty officers, specialized services, and remote monitoring.

The acquisition adds intelligence-led and specialized protective services to Protos’ platform.

Protos CEO Mark Hjelle said the transaction supports the company’s growth strategy to enter additional high-growth areas and that the combined capabilities will address clients’ evolving security requirements.

The deal represents Protos’ 12th acquisition since partnering with Southfield Capital.

No advisors or expected closing date were provided.