US authorities added the name of the Boston bombing suspect Tamerlan Tsarnaev to a terrorist database 18 months before the explosions, but did not follow up their inquiry.
Officials say the CIA made the request to add Tamerlan's name after the Russian government contacted them with concerns he had become a follower of radical Islam.
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The district's director of homeland security has said officials are planning for 800,000 to 900,000 people to attend the ceremony.
The Supreme Court is set to decide on whether disabled travellers are legally entitled to have priority use of wheelchair spaces on buses.
There will be some brightness, with the best of the sunshine towards the south and southeast where it will again be chilly.