According to court papers, suspects Azamat Tazhayakov and Dias Kadrybayev destroyed and concealed Dzhokhar Tsarnaev's backpack and laptop computer.
The charges say that the suspects decided to conceal the items after learning he was a suspect in the Boston Marathon Bombing.
More top news
The major party leaders' campaigns for the General Election will remain suspended on Wednesday following the Manchester terror attack.
Thousands of people have donated to help the families of the victims - as well as a homeless man who came to their aid.
Some children, particularly those who have been more directly affected, may show symptoms of stress and trauma.