Secret Service sex scandal keeps growing

(CBS NEWS) WASHINGTON - The sex scandal rocking the Secret Service is spreading.

Three more agents have stepped down in the wake of alleged activities involving prostitutes in Cartagena, Columbia last weekend. One more agent is now under investigation, and another has been cleared of serious misconduct. In all, 12 have now been in focus.

The U.S. military says 11 of its members are being investigated. That's up from the 10 previously believed to be involved. So far, they haven't been charged or placed in detention.

The latest departures, after several days of lie detector tests and interviews, follow the dismissal earlier in the week of two supervisors. David Chaney, who was allowed to retire, was a member of Sarah Palin's protective detail during the 2008 campaign. Greg Stokes was dismissed, but has the option to appeal. A third agent resigned.

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Agency officials briefed lawmakers on Capitol Hill Friday as investigators in Cartagena continued attempting to contact all the women who came to the Hotel Caribe last week before President Obama's arrival in Colombia.

The New York Post and New York Daily News have identified a woman, believed to be Dania Suarez, as the one whose dispute over payment ignited the incident. Neighbors at a gated community told CBS News it was her luggage being loaded into two taxis Friday.

Friday afternoon, the president was briefed for the first time briefed by Secret Service Director Mark Sullivan about the continuing investigation. The White House has been keeping its distance.

To see Bill Plante's full report, click on the video in the player above.