Technology giant Hewlett-Packard said Wednesday that it has terminated its relationship with The Experts, following a shooting at the Navy Yard in which an employee of the subcontractor, Aaron Alexis, killed 12 people.

In a letter sent to Thomas Hoshko, chief executive of the Florida-based company, an HP executive wrote that the tech giant “has lost all confidence in The Experts’ ability to meet its contractual obligations and serve as an HP subcontractor.”

The news is the latest blow to The Experts, which has come under scrutiny as reports emerged that Alexis was hired and retained despite past arrests and mental health issues.

“Based on what we now know about The Experts’ conduct, including its failure to respond appropriately to Aaron Alexis’ mental health issues and certain incidents recently reported in the press, HP has terminated its relationship with The Experts,” an HP spokesman said in a statement.

The Experts said in a statement that the decision will affect nearly 250 of its employees.

Read eyewitness accounts from the Navy Yard shooting.

“The Experts is disappointed in H-P’s decision, as we have continued to meet all of our contractual obligations,” the company said. “The Experts had no greater insight into Alexis’ mental health than H-P, particularly given that an H-P site manager closely supervised him, including during the events in Rhode Island.”

In Rhode Island this year, Alexis called police to report hearing voices and feeling vibrations through his hotel room walls.

Alexis, 34, was hired to help update and replace computer systems at Navy and Marine Corps installations. In recent months, he worked at multiple naval locations, including in North Carolina and Virginia.

The Experts has said it employed Alexis for about six months. The company said it confirmed his secret-level security clearance with the Defense Department after it hired him in September 2012 and again in late June 2013, after Alexis returned from a hiatus. The company has said it hired an outside company to handle two background checks of Alexis.

In the letter, Henry Dreschler, who oversees global contingent labor at HP, said that The Experts did not meet HP expectations for its subcontractors. As a result, all work covered by the companies’ agreement is suspended, Dreschler said, and HP said it will not place future orders with company.