SACRAMENTO  (AP) — A tip from the public led police in California’s capital city to arrest a 28-year-old man Wednesday in the stabbing of a U.S. airman hailed as a hero for helping thwart a European terror attack.

Air Force Staff Sgt. Spencer Stone was knifed three times in the torso on Oct. 8 in a fight near a bar in Sacramento, shortly after nightclub patrons applauded the 23-year-old for his role in tackling a gunman with ties to radical Islam on a Paris-bound passenger train in August.

James Tran, who lives outside Sacramento, is considered “the instigator” in the brawl that led to the stabbing, police Chief Sam Somers Jr. said at a news conference. He was arrested early Wednesday on a charge of attempted homicide.

A number of others were questioned in the attack but none has been arrested, Somers said. Police would not say how many others were questioned.

Stone’s injuries were so severe that police initially thought he could die, so they called in detectives who have been investigating public tips on the case ever since, Somers said.

One led to Tran in recent days, and arrest and search warrants were issued Tuesday while he was kept under surveillance.

Detectives moved in Wednesday as Tran drove in south Sacramento County and he was arrested without incident. Tran has a previous felony arrest and is affiliated with a gang, but that played no role in the fight, Somers said.

Investigators have said the assault had nothing to do with the European terror plot and involved an alcohol-fueled fight between two groups in a popular nightclub district. Somers said Tran and his group did not know who Stone was until they saw news reports later.

Stone was with three women and another man when other clubgoers praised him at Badlands, a nightclub in Sacramento’s Midtown district. Grainy surveillance video from outside a liquor store about an hour later shows a large man who appears to be Stone fighting a half dozen people at an intersection down the street.

The fight started as a verbal argument after one of the groups videotaped the other, Somers said without elaborating. The police chief would not confirm reports that Stone was helping a woman when the argument began but said Stone’s history shows that “if he feels that something is inappropriate or wrong, he will take action. I’ll leave it that way.”

The two parties then separated, but Tran started it up again, and the fight escalated. During the melee, Tran circled behind Stone and stabbed him multiple times in the back, Somers said.

He faces arraignment Friday on a charge of attempted murder, said Shelly Orio, a spokeswoman for the Sacramento County district attorney. She did not know if Tran had an attorney.

A separate video released by police showed two men and a woman fleeing in a vehicle, which has been recovered, Somers said.

Stone underwent about two hours of surgery for what hospital officials said were potentially life-threatening wounds. A 24-year-old woman who was with Stone was treated at a hospital for abrasions.

In August, Stone suffered a knife wound to the neck and a severely cut thumb when he and two childhood friends from Sacramento stopped the attempted terror attack. Stone, National Guardsman Alek Skarlatos and college student Anthony Sadler were vacationing in Europe when they tackled Ayoub El-Khazzani, who was carrying a Kalashnikov rifle, pistol and box cutter.

Stone is assigned to Travis Air Force Base, about 50 miles southwest of the state capital. He was promoted from airman to staff sergeant last week.