Caci International Inc. (NYSE: CACI) is buying a business that works with the U.S. Department of Defense and U.S. Federal Civilian Government to provide security and other technology services for $550 million. The transaction comes two days after President Barack Obama addressed the U.S., calling the Dec. 2 mass shooting in San Bernardino, California, a terrorist attack.

The target, L-3 National Security Solutions Inc., provides specialized services, including cyber security, intelligence, enterprise and mission information technology, command and control, big data and physical security, to various national security agencies. The Reston, Virginia-based business has more than 4,000 employees, and more than 90 percent of them have security clearances.

Arlington, Virginia-based Caci provides professional services and information technology to national defense, intelligence and other agencies. Caci expects the acquisition to add more than $1 billion in annual revenue. The company is financing the deal through term and revolving debt.

"The acquisition of NSS will strengthen our capabilities in key market areas and allow us to offer a broader array of IT solutions to our customers," says John Mengucci, COO of Caci.

There have been several security-related acquisitions recently. In August, the Carlyle Group (Nasdaq: CG) agreed to buy cybsercurity data firm Novetta from Arlington Capital Partners. Before that, Q2 Holdings Inc. (NYSE: QTWO) agreed to buy financial services security provider Centrix Solutions Inc.

Mergers & Acquisitions predicts more technology related deals, including cybersecurity transactions, will come in 2016. For more, read 16 Middle-Market Trends to Watch in 2016. For more on cybersecurity, see Hacking Drives Cybersecurity Deals