The crash early on Feb. 16 fatally injured the medics who were inside the ambulance, Tim McCormick and Cody Medley. McCormick, 24, of Greenwood died the morning of the crash and Medley, 22, of Indianapolis the next day.
Safety officials have said that as far as they know, the two were the first known emergency services workers in Indianapolis' history to be killed in the line of duty.
"This was clearly a tragic accident, and we again extend our sympathies to the families and friends of Cody Medley and Tim McCormick," Curry said. "However, we do not believe that the circumstances of the accident rise to the level of a crime."
Curry said Jade Hammer acknowledged she consumed alcoholic beverages before the crash, but her blood alcohol level was found to be .038, below Indiana's 0.08 legal limit for driving. Toxicology tests found no evidence of other substances in Hammer's blood.
An analysis of the crash determined Hammer was driving 35 to 40 mph in a 30 mph zone when she ran a flashing red light. The ambulance was traveling 45 to 50 mph. The medics were not on an emergency run at the time.
Curry said the Indiana Supreme Court has held that failure to stop at a red light doesn't support a charge of reckless homicide.
Hammer could not be reached for comment. There is no telephone listing for her locally.
Indianapolis EMS chief Dr. Charles Miramonti issued a statement thanking Curry and investigators.
"Their efforts serve to bring closure to this tragic chapter in our history and our personal lives," Miramonti said.