And for those decisions, how that operates and why, I refer you to the United States Secret Service.

WHITEHOUSE: Press Briefing

The first is, at 3:00 p.m. today the President will host a swearing-in ceremony for the new director of the United States Secret Service, Julia Pierson.

WHITEHOUSE: Press Briefing by Deputy Press Secretary Josh Earnest

And certainly her leadership skills and her character and her 30 years of experience at the United States Secret Service are the reasons why she was chosen.

WHITEHOUSE: Press Briefing by Deputy Press Secretary Josh Earnest

Christopher Falkenberg, president at Insite Security Inc. and former Special Agent of the United States Secret Service, cautions that it will take some time to know what had happened in Boston, but suggested that judging from photos and video the devices were small, and possibly home-made.

FORBES: Two Dead, More Than 100 Injured In Boston Marathon Bombings

Christopher Falkenberg, president at Insite Security Inc. and a former special agent with the United States Secret Service, cautioned that it will take some time to know what had happened in Boston, but suggested that judging from photos and video the devices were small, and possibly home-made.

FORBES: This post was last updated on Monday, April 15 at 11 PM ET.

We track important developments in homeland security policies and programs in the United States National Guard, the Federal Emergency Management Agency, the United States Coast Guard, U.S. Customs and Border Protection, U.S. Immigration and Customs Enforcement, United States Citizenship and Immigration Services, the United States Secret Service, the Transportation Security Administration, and Civil Air Patrol.

CENTERFORSECURITYPOLICY: Homeland Security

The Secret Service personnel have since been sent back to the United States.

CNN: STORY HIGHLIGHTS

Called Enhanced Standards of Conduct, the new guidelines given to all Secret Service personnel make clear that standards of behavior required in the United States apply on missions abroad, the sources said.

CNN: New investigation launched into prostitution scandal