MIAMI -- The suspicions airport security officials had when they saw the metal canister grew when they learned about the man who brought it in from the Middle East: a scientist who sparked a bioterrorism scare after he reported missing vials of plague samples seven years ago.

Officials shut down most of Miami International Airport overnight, roused nearby hotel guests from their beds and detained Dr. Thomas Butler until Friday morning, when he was released without charges, a senior law enforcement official said. Tests on the canister found nothing dangerous.

Prof. Butler, 70, is a world-renowned plague researcher who quickly became the focus of a federal investigation in 2003 when he reported that 30 vials of plague samples possibly had been stolen from his Texas Tech University lab.

WASHINGTON -- A former treasurer of the National Republican Congressional Committee admitted in court Friday that he stole more than $844,000 from the NRCC and several other political fundraising committees.

Christopher Ward, 41, pleaded guilty in federal court in the District of Columbia to interstate transportation of stolen property. Under the plea agreement, prosecutors will seek a 37-month prison term and Mr. Ward will have to pay back his victims.

Mr. Ward, once a trusted figure in Republican circles who had served as treasurer for 83 GOP committees in a decade, funneled the money from committee coffers over seven years, according to the plea agreement. Some of the cash went to mortgage payments and remodeling and landscaping at his Bethesda, Md., home, authorities said in court documents filed in 2008.

MURFREESBORO, Tenn. -- Federal investigators have decided a suspicious fire that damaged construction equipment at the site of a future mosque in Tennessee was arson.

U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives agent Steven Gerido said Friday that lab tests confirmed an accelerant was used in the fire early last Saturday in Murfreesboro.

The site is the location for a new Islamic Center of Murfreesboro, which has drawn increasingly vehement opposition, including protest marches and some vandalism.

CHICAGO -- Chicago's seasonal ritual of boat parades may be scuttled as five states ask a judge to head off an invasion of Asian carp by blocking access to Lake Michigan.

Boats come out of winter storage along the Chicago and Calumet rivers each spring and motor through locks into the lake, where they harbor until autumn.

Michigan and four other states will argue at a Sept. 7 hearing that one way to shut out the carp is to close the locks. Boaters in the nation's third-largest city say that would strand them in dry dock or, for sailboats, cost thousands of dollars to have vessels transported overland.

Albuquerque, N.M., police briefly evacuated a Goodwill store Thursday after someone left a pistol, ammunition, a World War Il-style inert grenade and some marijuana in a collection box. ... Authorities say a Helena, Mont., teen sent out a text message last week in search of pot, but instead of contacting the drug dealer, he hit a wrong number and inadvertently sent the message to Lewis and Clark County Sheriff Leo Dutton.

-- Compiled from news services

Washington correspondent Daniel Malloy writes the "Pittsburgh On The Potomac" blog exclusively at PG+, a members-only web site of the Pittsburgh Post-Gazette. Our introduction to PG+ gives you all the details.