Nearly five years after a Fairfax County police officer shot and killed an unarmed man outside his townhouse, the county has agreed to pay the man's parents $2 million to settle their lawsuit against the officer.

The death of Salvatore J. Culosi, a 37-year-old optometrist who lived in the Fair Oaks area, sparked outrage over the use of a SWAT team to arrest a man suspected of the nonviolent crime of taking bets on football games. Fairfax police were aware that Culosi had no criminal history or connection to weapons.

The SWAT officer who fired the shot, Deval V. Bullock, said his .45-caliber pistol accidentally discharged Jan. 24, 2006, after his vehicle door bumped his left side as he aimed at Culosi with his right hand, causing a sympathetic reflex response.

The Fairfax prosecutor in 2006, Robert F. Horan Jr., ruled that the shooting was not a criminal act. To prove manslaughter in Virginia, the shooter must show "negligence so gross as to indicate a callous disregard of human life." A federal civil rights investigation also cleared Bullock.

But Chief David M. Rohrer suspended Bullock without pay for three weeks and removed him from the SWAT team. Rohrer also changed the way SWAT teams are assigned and how police shootings are investigated. He acknowledged the police role in the shooting the day after it occurred, offered his condolences to Culosi's family and later issued a report on the incident.

Culosi's parents, Salvatore and Anita Culosi, filed suit in federal court in Alexandria in 2007 and then saw their day in court delayed by pretrial hearings and appeals of pretrial rulings. U.S. District Judge Leonie M. Brinkema dismissed Fairfax County, Rohrer and the head of the SWAT team as defendants, leaving only Bullock, whose legal fees and any potential damages would be covered by the county. The trial was scheduled to begin next week.

The Culosis' attorneys, Bernard J. DiMuro and Michael Lieberman, launched their own investigation and devised a theory of the shooting that differed drastically from the police version, court filings show.

Calculating the trajectory of the shot that entered Culosi's side and pierced his aorta, and the location of Bullock's shell casing near where Culosi fell, the lawyers argued that Bullock had moved away from his sport-utility vehicle and was only eight to 10 feet from Culosi - not 20 feet and emerging from his vehicle, as Bullock said - when he fired.

Police lawyers said in court briefs that Culosi may not have been standing perfectly upright, which would affect the trajectory calculations, and that the shell casing might have blown or been kicked down the slight incline from where Bullock fired.

Though Bullock was following proper procedure by aiming at his target, he was not supposed to have his finger on the trigger. Bullock told police investigators in 2006, "my finger rolled and somehow got on the trigger and pulled the trigger," an internal affairs interview transcript shows.

DiMuro and Lieberman hired experts to testify that the shooting couldn't have happened the way Bullock said, court records show, and produced an animated video showing how the trajectory of the bullet didn't match Bullock's story - but it did match a close-range shooting.

Brinkema ruled that three Culosi experts could testify. And last week, she ruled that the animation could be shown to the jury. Settlement talks heated up, and in a closed session Tuesday night, the Fairfax Board of Supervisors approved the payment, county spokeswoman Merni Fitzgerald said.