Boston bomb suspect in custody -CNN

           
Authorities have arrested a suspect in the Boston Marathon bombings based on security video that showed a man depositing a bag at the bomb scene before the blasts, CNN reported on Wednesday, citing U.S. and Boston law enforcement sources.                                

Earlier, the FBI said that an investigation into mail containing a suspicious substance addressed to a lawmaker and to President Barack Obama has not found a link to the attack in Boston.          

"The investigation into these letters remains ongoing, and more letters may still be received. There is no indication of a connection to the attack in Boston," the FBI said in a statement.
            
The envelope addressed to Obama was immediately quarantined by the U.S. Secret Service, the FBI said.              

Filters at a government mail screening facility preliminarily tested positive for ricin on Wednesday morning and mail from that facility was being tested, the FBI said.          

"Only a full analysis performed at an accredited laboratory can determine the presence of a biological agent such as ricin. Those tests are currently being conducted and generally take 24 to 48 hours," the FBI said.    


REUTERS