The man accused of opening fire with a rifle from a rooftop onto a crowd of people watching a July Fourth parade near Chicago, turning the holiday celebration into another national tragedy, was charged on Tuesday with seven counts of first-degree murder.

If convicted, the suspect, 21-year-old Robert E. Crimo III, would face a maximum sentence of life in prison without the possibility of parole, Illinois states attorney Eric Reinhart said, announcing the charges at a news conference.

Reinhart said the first-degree murder charges would be followed by dozens of additional charges before the investigation is over. The prosecutor said he would ask that Crimo remain held in custody without bail at the suspect's first court appearance, scheduled for Wednesday.