Like so many brutality cases, it was a video of Buffalo Police Officer Corey Krug that first caught the attention of federal prosecutors.
Shot by a WKBW-TV photographer, the 2014 Thanksgiving Day video shows the 15-year police veteran hitting a man repeatedly with a nightstick during a confrontation on Chippewa Street.
Now, more than four years later, it will be a focal point in Krug's jury trial.
"He is in essence a bully with a badge," Assistant U.S. Attorney Aaron J. Mango said in his opening statement Tuesday. "No one, not even someone with a badge, is above the law."
Krug's trial before U.S. District Judge Richard J. Arcara will focus on three separate allegations of excessive force, one of them dating back nearly nine years.
In his defense, the officer will argue that his use of force was justified.
"We don't want to make a mistake that takes the handcuffs off criminals and puts them on the police," defense attorney Terrence M. Connors told the jury Tuesday.
In the Thanksgiving Day encounter on Chippewa Street, the video shows Krug hitting a man, Devin Ford of Lackawanna, repeatedly with his nightstick.
Krug also is accused of grabbing Ford and pushing him against a car and then to the ground.
When the video of their encounter first became public, the FBI investigated and found evidence of two other alleged incidents of brutality, both of them documented in earlier civil suits against the officer.
"The evidence will show that the defendant lost his cool and used excessive force on them," Mango told the jury.
At one point, the prosecutor acted out the three incidents, using "whack, whack, whack" and "boom, boom," to describe Krug striking the victims.
Connors told a far different story and suggested more than once that Ford is lying in order to bolster his lawsuit, which is still pending.
He also argued that it was Ford, not Krug, who instigated the confrontation and that his client's use of force was justified.
The defense also is expected to introduce evidence of Krug's record as an officer, including his more than 1,000 arrests and his reputation for working in the toughest neighborhoods and dealing with everyday risks.
"It's part of their life, it's part of their profession," Connors said, "but it's also real danger."
In the first of the three incidents, in August of 2010, Krug is accused of hitting Marcus Worthy of Langmeyer Street with a metal flashlight and then failing to disclose his use of the flashlight in a report to superiors.
A few months later, Krug was again accused of using a flashlight, this time to hit Daniel A. Rashada of Bissell Avenue.
Rashada said he was walking home when the officer confronted him and struck him in the face. Prosecutors said the blow caused swelling and a scar.
"It's unmistakable," Mango said of a mug shot showing Rashada's injuries. "A gash under his right eye, blood streaming down his face."
Rashada filed a civil suit against Krug a few months after the incident and eventually settled out of court with the city for an undisclosed amount of money. Worthy's suit is still pending.
Connors claims prosecutors are exaggerating both the cause and extent of Rashada's injuries that night in 2011. He said the cut under Rashada's eye occurred when the two men slipped on the ice and fell.
"Corey never hit him with a flashlight," he said. "It never happened."
Even before the trial began Tuesday, the defense tried to eliminate three pieces of evidence – each one of them an audio recording of police officers working with Krug on Chippewa that night in 2014.
On the recordings, you can hear an officer say, "Corey, Corey, Corey, relax," and another officer warning Krug that he is being videotaped.
The trial also started with one of the 12 jurors excused because of concerns about his son and a bullying encounter with one of Krug's relatives several months ago. The juror indicated the bullying occurred well before he was picked for jury duty and had nothing to do with the case.
Krug, who is currently suspended with pay, is charged with deprivation of rights under color of law and faces a maximum sentence of 10 years in prison.
His trial, postponed for two days because of the weather, resumes Friday.