Seven of nine defendants ranging in age from 24 to 45 who were arrested May 4 after police interrupted a late-night party beneath the Bloomfield Bridge had most of the criminal charges against them dropped Thursday afternoon during a preliminary hearing.

Dropped charges included felony offenses for rioting and misdemeanor offenses for failing to disperse. They were instead each found guilty of a summary offense of disorderly conduct for being at the park after 11 p.m. and given a $300 fine that cannot be repaid through community service.

Among the seven who received the light sentences was Lauren Jurysta, 24, of Pittsburgh, who faced a felony charge of second-degree aggravated assault. Police said she flicked a cigarette at Pittsburgh Police Sgt. Charles Henderson after calling him an "asshole" and "fascist pig."

Her arrest, police said, was the first after officers responded to a 911 complaint about a large, disorderly party under the bridge. A live band was set up and about police estimated that 100 people were at the park without a permit. Members of the party became upset and demanded to know why Jurysta was being arrested. The resulting confrontations led to the other eight arrests, according to the testimony by police officers and their supervisors Thursday.

Two of the nine defendants plead not guilty, and will go to trial.

Jason Oddo, 26, of Irwin, plead not guilty to a felony charge of third-degree aggravated assault (downgraded by the judge from a second-degree aggravated assault charge) and four misdemeanor charges: disorderly conduct, obstructing administration of law or other government, resisting arrest and possessing instruments of crime. A third-degree felony charge of rioting was dismissed.

Police said Oddo used pepper spray against a police officer who was pursuing him after Oddo ran from him to avoid arrest.

Kathleen Tierney, 29, of Braddock, also plead not guilty and will go to trial on misdemeanor charges of criminal mischief and disorderly conduct. Police said she punctured a tire on a police vehicle as she left the party.

Elise Delong, the attorney representing Jurysta, said the results of the hearing "were probably fair all around."

"They were in violation of the law," she said. "Automatically, all of them were wrong because they were in a park after 11 p.m."

The party and the arrests came a day after police reported vandalism to the nearby Sciullo Field, which serves as a memorial to Pittsburgh Police Officer Paul Sciullo, who was killed along with two other police officers in 2009, after a standoff in Stanton Heights.

Graffiti was found and vandals attempted to remove a memorial badge from the park's sign, according to news reports at the time.