Police in the US city of Albuquerque, New Mexico, say they have arrested their “primary suspect” in the killings of four Muslim men.
Muhammad Syed, 51, was held on Monday and is charged with the murders of two of the men. Multiple firearms were recovered from his home, say police.
Police say they are working with investigators to charge the Afghan with the other two deaths.
The deaths took place over the past nine months.
The last three killings happened in the past two weeks.
Police chief Harold Medina announced the breakthrough on Tuesday, saying they had tracked down a vehicle believed to be involved and detained the driver.
Investigators say the attacks may have been motivated by personal conflict.
The suspect came to the US from Afghanistan “in the last several years”, police said.
Three of the victims were originally from Pakistan and attended the same mosque. Officers said they were “ambushed with no warning, fired on and killed”.
A fourth man, Mohammad Ahmadi, originally from Afghanistan, was killed last November.
Kyle Hartsock, deputy commander of the police criminal investigations division, said the suspect was arrested after his car was stopped and his home was simultaneously searched by a Swat team.
He said that a tip from the public had led to his arrest just two days after police distributed a photo of the suspect’s vehicle.
In a news release, police said during a search of Mr Syed’s home “detectives discovered evidence that shows the offender knew the victims to some extent and an interpersonal conflict may have led to the shootings”.
But in Tuesday’s press conference, law enforcement did not go into reports that the suspect was a Sunni Muslim who had targeted the victims because he was upset at his daughter marrying a Shia Muslim.
Mr Hartsock said: “We’re not really clear if that was the actual motive, if it was part of a motive, or if there’s a bigger picture that we’re missing.”
Albuquerque Mayor Tim Keller said in a statement that he hopes the “swift action brings an increased sense of safety for so many who are experiencing fear from the recent shootings”.
On Monday, US President Joe Biden said he was “angered and saddened by the horrific killings”, adding that “these hateful attacks have no place in America”.
Police have not said the attacks were hate crimes.
The search for the suspect had steadily grown in size over recent days after New Mexico Governor Michelle Lujan Grisham said she was sending additional law enforcement officers to the city to aid investigators.
Several organisations had offered significant rewards for information leading to the arrest and conviction of a suspect.
Ahmad Assed, a spokesman for the Islamic Center of New Mexico, told the BBC the killings have been horrific for the city’s Muslim community.