A Canadian tourist in town for the Kentucky Derby was shot to death while fighting off three people who robbed him at random during a crime spree amid the festivities of the famed horse race, police said Monday.

Three people have been arrested in the killing late Saturday, and police said the trio was responsible for a string of armed robberies.

The victim and a friend were walking back to their Louisville hotel, hours after the Derby, when the suspects picked them out to rob, said Louisville Metro Police Lt. Todd Kessinger. The area has several hotels not far from the Churchill Downs racetrack. The robbery appeared to be random, and the tourist was shot during a struggle with the attackers, Kessinger said.

Louisville authorities had not yet identified the victim. Police said he was from Toronto.

Police said they arrested a man, his sister and his sister's boyfriend on Sunday.

Tyrone Thomas Jr., 19 is accused of firing the fatal shots, according to police records. His girlfriend, Fatima Abu-Diab, 20, allegedly drove the getaway car. Her brother, Fahed Abu-Diab, was also involved, police said.

Each was charged with murder and a dozen counts of armed robbery.

Police believe the three committed a string of armed robberies Friday and Saturday around hotels and apartment complexes, coinciding with the 141st running of the Kentucky Derby. Churchill Downs officials said 170,513 people crammed into the historic track, surpassing the previous attendance record of 165,307 set in 2012.

Police followed up on leads from witnesses to make the arrests, Kessinger said.

"It looks like they were concentrating in a general area and that they were targeting people that were walking on the street or walking through parking lots," Kessinger said.

Court records show Thomas, the alleged gunman, was arrested earlier this year on drug charges. On April 1, a police officer who stopped him in Louisville wrote in a police report that he could smell marijuana wafting from the car. Thomas allowed the officer to search his Chevrolet, where he found three Xanax pills, marijuana and a loaded Smith & Wesson pistol. Those charges remain pending.

Fatima Abu-Diab and Fahed Abu-Diab were also charged Saturday with drug offenses.

Fatima Abu-Diab allegedly had a small amount of heroin, loose Xanax pills and several thousand dollars in cash on her when she was arrested, the police report says. She was sentenced to six months in jail last year on a misdemeanor assault charge.

Fahed Abu-diab had 20 loose Xanax pills, marijuana and about $9,000 cash when arrested, the police report says. He pleaded guilty earlier this year to marijuana possession.

Churchill Downs spokesman John Asher said Monday that track officials were saddened by "this senseless tragedy."

"We're encouraged that arrests have been made and we join our entire community in offering thoughts and prayers to the victim's family and loved ones," Asher said.