A jury found Dennard guilty of the felony charge and a misdemeanor count of resisting arrest, but acquitted the former Nebraska standout of third-degree assault against another man, Lancaster County Attorney Joe Kelly said.
Dennard faces up to five years in prison for the officer assault and up to a year for resisting arrest, Kelly said. His sentencing hearing is April 11.
Kelly said he did not yet know whether his office would urge the judge to sentence Dennard to prison time.
Dennard was arrested just after 2 a.m. on April 21 outside a bar in Lincoln. A police report said officers outside the bar witnessed a verbal altercation between Dennard and another person that appeared to be escalating before other people separated the two.
The officers approached the group and told Dennard twice he "needed to leave the area," according to a police affidavit. The affidavit said Dennard was walking away when an officer saw him punch another man.
Officer Ben Kopsa then ran up to Dennard, told the football player he was under arrest and tried to handcuff him. Officers said Dennard pulled away, then punched Kopsa in the face.
During his trial, Dennard acknowledged he may have resisted arrest, but denied punching the officer.
The fight occurred five days before the 2012 NFL draft. Dennard was the 2011 Big Ten defensive back of the year and had been projected to be a second- or third-round pick before his arrest. The Patriots took Dennard in the seventh round and he is coming off his rookie season.
Dennard remains free on bond, said his attorney, Terry Dougherty of Lincoln.
"We're disappointed that he was convicted, but that's the jury's verdict," Dougherty said. "Now we need to turn our attention to the sentencing phase of the trial."