TSA replaces acting head and makes major changes

The acting head of the TSA is out of a job, and it's just one of the major steps the Secretary of Homeland Security is taking after a shocking report.

ABC News first reported on Monday that the TSA screeners missed 95% of the fake bombs and weapons that a DHS testing team tried to sneak through the system.

In one test, an undercover agent was stopped after setting off an alarm at a magnetometer.

But, TSA screeners failed to detect a fake explosive device that was taped to his back during a follow-up pat down.

And, now the fallout.

Secretary of Homeland Security Jeh Johnson is so upset about the security lapses. He's moved the acting head of TSA, Melvin Carraway and replaced him with his deputy, Mark Hatfield.

Johnson's also ordered immediate major changes to airport screeners that will revise standard operating procedures for screenings, provide intensive training for supervisors, retest and re-evaluate screening equipment.

TSA screeners can expect even more random, covert testing.

John Pistole was the head of the TSA until earlier this year. He says secret tests like this one are designed to improve the system.

"Any time there's a high rate of misses that causes concern in one of three ways. One is the technology is not working right, two the standard operating procedures aren't working right, or three the officers themselves aren't doing something right," he says.