Kelly said Friday he met with Boston officials after the bombing at the marathon earlier this year and have gleaned some lessons on how to better secure the 26.2-mile route.
He says there will be four dozen bomb-sniffing dogs, mobile cameras, air and water units and scores of officers on the ground. They will also use their high-tech video surveillance systems that can detect when an item is left in one spot too long.
Volunteers have been pre-screened and will be screened again on the day of the race.
Kelly and race organizers are encouraging spectators to leave bags at home. If bags are brought, they may be searched.