Why do some U.S. airports have private security, but others use TSA?

KANSAS CITY, Mo.— If you've traveled by plane, you can probably picture this scene: Passengers line up to present their IDs to an airport officer, put their carry-on luggage on a conveyor belt and walk through a scanner.But one detail at Kansas City International Airport is a bit unique.
The uniformed officers who scan IDs and screen carry-on bags wear badges and U.S.flag patches, but they're not Transportation Security Administration (TSA) officers — they're private contractors.
It's a distinction many passengers don't seem to notice."It's news to me," said Natasha Greenway, holding the handle of her son's stroller before catching a flight to Philadelphia."I didn't even notice," says Kim Eckels, who was traveling to Portland, Ore., with her family.With a laugh, she added, "I taught my kids not to question anything going through security.
Just keep your mouth shut and go."That attitude is shared by many travelers, who can be forgiven for not realizing that the officers politely but firmly guiding them through the screening process work not for the government but for VMD Corp., based in McLean, Virginia.As more airports consider going private rather than using federal officers, companies like VMD are eager to show they can keep passengers safe — and satisfy the TSA's oversight and standards."We do have TSA" at the airport, noted Gabe Murphy, VMD's program manager at Kansas City International.Private employees are responsible for everything from checking IDs to screening passengers and baggage.
But Murphy said the TSA also has a security team there whose job is to "basically audit us and make sure that we're following all the processes and procedures that are outlined by TSA."Using the acronym for standard operating procedure, he added: "Their SOP is our SOP."The federal-private divide dates to the creation of the TSA in the wake of the terrorist attacks of Sept.11, 2001.
In the process, the government gave airports a choice of staffing checkpoints with fed...