But by Tuesday night, Senate Sergeant At Arms Terrance Gainer said the police believe there was only one shooter — Aaron Alexis, who was killed by police at the scene.

As a result, the Senate will start work at 10 a.m., and senators are likely to spend part of the day addressing the Monday shooting.

Some debate may also occur on S. 1392, the Energy Savings and Industrial Competitiveness Act. This legislation is aimed at promoting energy-saving building codes, although the Senate struggled last week to reach a deal on amendments.

A vote on two judicial nominations may also happen today. They are Patricia Campbell-Smith and Elaine Kaplan, who have both been nominated as Federal Claims Court judges.

The House starts at noon, and later in the afternoon it will consider up to five suspension bills. They are:

— H.R. 1410, the Keep the Promise Act, preventing approval of new casinos in Phoenix, Arizona.

— H.R. 2449, authorizing the extension of an agreement between the U.S. and South Korea on civil nuclear power.

— H.R. 301, creating a special envoy to promote religious freedom of religious minorities in Asia.

— S. 793, the Organization of American States Revitalization and Reform Act.

— H.R. 3092, the Missing Children's Assistance Reauthorization Act, authorizing $40 million a year in funding for the National Center for Missing and Exploited Children, and strengthening the operation of the Center.