Posted: 11:10 PM Chase moved into high gear with murder of MIT campus police officer.

Posted: 11:07 PM Government invoking "public safety exception."

Posted: 2:57 PM Denver pot holiday bringing crowds, tight security

Posted: 1:38 PM The FBI is at the northern New Jersey home of the sister of the Boston Marathon bombing suspects.

Posted: 1:28 PM Gov't sources: Boston bomb suspect went to Russia

Posted: 11:52 AM Boston bombing suspect's uncle: `Turn yourself in, and ask forgiveness' from the victims.

Updated: 11:38 AM Would continue to exclude gay adult leaders.

Posted: 11:38 AM Family: We sought help for accused ricin mailer

Updated: 12:08 PM Police find SUV believed linked to Boston suspect

Posted: 10:19 AM Chief: Slain MIT officer was dedicated, well liked

Posted: 9:56 AM DPS: 12 bodies recovered after Texas plant blast

Updated: 8:19 AM A glance at the search for Boston bomb suspects

Updated: 2:20 PM Miss. man charged with threatening Obama, others

Updated: 12:20 PM Police: Unclear how many trapped after Texas blast

Posted: 12:02 PM Men of Interest Seen in Boston Marathon Bomb Video

Updated: 10:19 AM Plant explodes Wednesday night near Waco.

Posted: 8:24 AM Boston fund to be administered by 9/11 Victim Compensation Fund manager.

Posted: 10:22 PM It happened near Waco, Texas.

Posted: 9:24 PM The FBI has identified a Mississippi man suspected of mailing letters containing poisonous ricin as 45-year-old Paul Kevin Curtis.

Posted: 4:37 PM Senate rejects bipartisan plan expanding background checks, major blow to gun control effort .

Updated: 4:56 PM Associated Press is reporting that federal government officials are denying that a suspect in the Boston Marathon bombing is in custody.

Updated: 12:22 PM The U.S. Secret Service says it has intercepted a letter addressed to President Barack Obama that contained a "suspicious substance."

Posted: 11:32 AM Law enforcement officials say a second letter sent to the U.S. Senate has been intercepted and is being tested for poisonous ricin.

Updated: 11:11 AM Authorities have recovered the pressure cooker lid and piece of circuit board from Boston bombings.

Posted: 10:15 PM Family does not want victim's name released.