Ammar Harris was arrested by a team of police and federal agents in North Hollywood, Las Vegas police Capt. Chris Jones said.
The 26-year-old Harris is a self-described pimp who was the subject of a multi-state manhunt following the Feb. 21 gunfire and chain-reaction crash.
Police say he fired at least five shots from an SUV into a Maserati sports car, killing a self-promoted rapper who he argued with earlier in the valet area of a Las Vegas Strip resort.
The Maserati slammed into a taxi, killing the driver and a businesswoman from Washington state.
Earlier in the day, police said they had found and talked with all three women who were in the SUV with Harris.
Late Wednesday, police found SUV passenger Tineesha Lashun Howard in another state, and Jones said for the first time that police previously found and interviewed two other women who were with Howard in Harris' black Range Rover SUV during the shooting.
Jones wouldn't release the names of the other passengers in Harris' SUV, but said none of the three passengers had been charged with a crime. Police are concerned about their safety, the police captain said.
Howard, a 22-year-old from Miami with a history of prostitution arrests, also uses the names Yenesis Alfonzo or Yani. She was identified by police on Tuesday as a person of interest in the case who might have been in danger.
Las Vegas police also sought Thursday to stop the circulation of several photos the department issued Tuesday and Wednesday in the search for Harris. Police said they depict people other than Howard.
Harris was arrested last year in Las Vegas in a 2010 prostitution case using the name Ammar Asim Faruq Harris. He was charged with robbery, sexual assault, kidnapping and coercion with a weapon, and police sought charges of pandering by force and felon in possession of concealed weapon. Court records show that case was dismissed last June.
Harris was convicted in South Carolina in 2004 of felony possession with intent to sell a stolen pistol and convicted that same year in Atlanta of a misdemeanor marijuana possession charge.