WATCH: Letter Addressed To Mississippi Senator Tests Positive For Ricin

An envelope addressed to Sen. Roger Wicker of Mississippi tested positive Tuesday for ricin, a potentially fatal poison, authorities said, heightening concerns about terrorism ... Read More

Outpouring of Support for Family of Boy Killed by Explosion

The family of the 8-year-old boy killed in the Boston marathon bombings is struggling to cope with the boy's death as well as "serious" injuries to the boy's sister and mother. Read More

WATCH: Bird Flu a 'Truly Nasty Virus,' Expert Says

A new strain of bird flu has been reported in China, and it has sickened 63 people and killed 14. Read More

WATCH: Doctor: Marathon Victims Had Nails, BBs In Wounds

Doctors say they removed a host of sharp objects from children and adults injured by the Boston Marathon explosions. Read More

Texas Woman Self-publishes, Hits Best-Seller Lists

After a feverish month of inspiration, Colleen Hoover had finally fulfilled her dream of writing a book. Read More

WATCH: Boston Bombings: Mystery 'Man on the Roof'

Photos taken of the Boston Marathon explosion carnage showed images of smeared blood on the sidewalk, blown out windows and bystanders rushing to aid multiple people who had lost limbs and suffered ot Read More

Massive Quake Kills At Least 46 Along Iran-Pakistan Border

A major earthquake described as the strongest to hit Iran in more than half a century flattened homes and offices Tuesday on both sides of the Iran-Pakistan border, killing at least 46 people in the s Read More

WATCH: Supreme Court Rejects Challenge To NY Concealed Weapon Law; Could Impact Maryland Law As Well

The Supreme Court on Monday turned back a challenge to a law in New York state that requires people to prove they have a special need for self-protection in order to seek a permit t... Read More

WATCH: Senate 'Gang Of Eight' Immigration Bill To Hit Senate Floor Today

The Senate "Gang of 8" that has been leading the charge on immigration reform has signed off on a comprehensive bill that will be introduced Tuesday, ABC News has learned exc Read More

DC Responds To The Boston Terror Strike With More Visible Security

Commuters in D.C. saw signs of heightened security as they traveled to work Tuesday, with a more visible police presence than normal, but city officials are urgin... Read More