Ralfy Olivas felt the impact from the officer's beanbag shotgun but did not stop. He heard police order him to drop the weapon but did not comply.
Instead he charged forward, a butcher knife in his hand, and forced officers to shoot and kill him, his family said Thursday.
"My cousin wanted to die," said an emotional Victor Chavez, 21, Olivas' cousin and close friend.
Olivas, 23, was identified by Chavez after Thursday morning's deadly police shooting in the northwest valley.
Police said the incident stemmed from an argument Olivas had with his mother about 7 a.m. at 7704 Musical Lane, near Buffalo and Westcliff drives. When the argument intensified, she called 911. Olivas then left the home.
As officers arrived in the neighborhood they encountered Olivas, walking alone toward them on Firestone Drive.
Capt. Patrick Neville, who oversees the department's Robbery and Homicide Bureau, said Olivas refused multiple commands to drop the knife.
One officer first tried to subdue him with a nonlethal beanbag shotgun, but Olivas continued to approach. When he did not drop the knife, three officers shot him multiple times, police said.
"At some point the officers felt fear for their lives," Neville said.
Police did not confirm that the incident was a suicide-by-cop but said they were investigating that possibility.
Neville said the mother told dispatchers her son was "out of control." He did not know what the argument was about, but the mother was not hurt.
Chavez said their close-knit family has been devastated. Olivas' girlfriend was in silent shock, and his mother was in shambles, he said.
"She blames herself for calling the cops in the first place," he said. "My aunt called the police to settle down a dispute, and Ralfy saw it as a way out. This was never supposed to happen."
Chavez was not at the home when the argument happened but said the dispute wasn't physical. He said his cousin would never hurt anyone; he was not a violent person and did not take drugs.
"They argued like any other mother and son would argue," he said. "He was just a fun-loving guy who got stressed out to the point of breaking."
Olivas was pronounced dead at University Medical Center, but one neighbor said his body lay motionless in the street for at least 10 minutes before the ambulance arrived. The ambulance left the scene without lights or sirens, the neighbor said.
The neighbor, who lives across the street from Olivas' home, said she was awakened by four or five gunshots just before 7 a.m. She looked out her window and saw the body and then saw Olivas' mother running down the street and screaming. The woman was followed by a younger woman, who the neighbor believed was Olivas' sister, she said.
"I'm just sick to my stomach. I feel so bad," the neighbor said.
She said Olivas' family moved to the neighborhood several months ago and kept to themselves. She and her husband did not hear any disturbance before officers arrived and gunshots were fired.
The officers have been placed on paid administrative leave pending an internal investigation. Their names will be released Saturday.
Thursday's shooting was similar to an incident in September 2009, when mentally distraught 15-year-old Tanner Chamberlain was shot in the head by police as he held a knife to his mother's neck.
Chamberlain's mother, Evie Oquendo, had called 911 after Chamberlain attacked her during a domestic disturbance.
That shooting was ruled justified by a coroner's inquest jury.
She later sued police for her son's death, stating she never felt her life was threatened and had begged officers not to shoot her son.
The last fatal officer-involved shooting in Las Vegas was July 4, when 54-year-old Luis Carlos Silva was shot and killed by officers after a domestic disturbance at his northeast valley home. Las Vegas police officers have been involved in 12 incidents this year in which at least one officer fired a weapon on duty. Nine of those incidents resulted in deaths.
Contact reporter Mike Blasky at mblasky @reviewjournal.com or 702-383-0283. Review-Journal reporter Antonio Planas contributed to this report.