US prosecutors have charged a suspect with seven murders over Monday's Independence Day parade shooting in Chicago.
21 year-old Robert Crimo is accused of shooting his victims from a rooftop.
Officers believe he had planned the attack for weeks, and had legally bought the rifle he used.
Lake County State's attorney Eric Rinehart says more charges will be brought against him.
"These seven counts of first degree murder will lead to a mandatory life sentence should he be convicted, without the possibility of parole."
US vice president Kamala Harris has visited Highland Park where the attack happened during a parade.
She says the country has got to be "smarter" when it comes to gun controls.
"We;ve got to take this stuff seriously, as seriously as you are, because you have been forced to have to take it seriously.
"The entire nation should understand, and have a level of empathy to understand, that this can happen anywhere, in any peace loving community."
