All the charges against two people who inadvertently caused a bioterrorism scare were dropped.
The sprinkled powder forced hundreds to evacuate an IKEA furniture store in August.
New Haven ophthalmologist Daniel Salchow, 36, and his sister, Dorothee, 31, who was visiting from Hamburg, Germany, were charged with first-degree breach of peace, a felony.
The charges were tossed out Thursday after Daniel Salchow agreed he and his sister would pay $4,000 (2,724 EUR) to local charities, the New Haven Register reported. However, prosecutors still can reopen the case if the Salchows do the same thing again in the next 13 months.
Dorothee has returned to Germany and prosecutors agreed not to require her to appear in court.
Daniel Salchow and his attorney, Michael Jefferson, said they were pleased with the resolution but still believe authorities overreacted.
"We felt all along it was an innocent activity," Jefferson said. "In a post-911 world, at some point somebody has to stand up and say, 'Enough is enough.' We can't be held hostage to fear as a society."
The siblings set off the scare while organizing a run for a local chapter of the Hash House Harriers, a worldwide group that bills itself as a "drinking club with a running problem."
"Hares" are given the task of marking a trail to direct runners, throwing in some dead ends and forks as challenges. In August, the Salchows decided to route runners through the massive IKEA parking lot.
Police fielded a call that someone was sprinkling powder on the ground. The store was evacuated and remained closed the rest of the night. The incident prompted a massive response from police in New Haven and surrounding towns.
Daniel Salchow biked back to IKEA when he heard there was a problem and told officers the powder was just harmless flour, which he said he and his sister have sprinkled everywhere from New York to California without incident.
New Haven officials maintain their response was warranted.