US parade gunman 'wore women's clothing'

Officers investigate the scene of a mass shooting in Chicago
The 21-year-old Chicago parade shooting suspect bought his gun legally, officials say. -EPA

The suspected shooter who attacked an Independence Day parade in a Chicago suburb bought his gun legally, fired more than 70 rounds into the crowd from a roof and dressed in women's clothing in order to blend into the crowd afterwards, local officials say.

The suspect, 21-year-old Robert E Crimo III, was taken into custody on Monday after surrendering to police. 

Police said he had planned the attack for several weeks and authorities were still considering what criminal charges to bring.

Police said they did not know what the motive was for the shooting.