Muhammad Syed is also suspected in a fourth killing, in murders that resonated across the US Muslim community.
A man has been charged with a third killing in a string of attacks on Muslims in the US state of New Mexico, which spread fears of religious and sectarian hatred across the country.
Muhammad Syed, 51, had previously been charged with two of the killings – that of café employee Aftab Hussein, who was killed on July 26, and city planning director Muhammad Afzaal Hussain, who was killed on August 1.
When Syed was charged on August 9, he was also considered the main suspect in two other killings.
On Monday, he was charged with the August 5 killing of trucking business owner Naeem Hussain after evidence from mobile phones linked him to the ambush-style attack.
He remains a primary suspect in a fourth murder of grocery store and café owner Mohammad Ahmadi, 62, which occurred in November 2021. Syed has denied involvement.
The killings initially sparked fears across the US that an attacker was targeting Muslims based on their religion, with US President Joe Biden saying the attacks “have no place in America”.
The arrest of Syed, a refugee from Afghanistan who has lived in the US for five years, then prompted speculation that the killings could have been motivated by Sunni-Shia divisions, with several national Muslim associations condemning the possible “sectarian hatred”.
Syed is Sunni and three of the victims are Shia. The alleged attacker had reportedly previously taken issue with his daughter’s decision to marry a Shia man.
However, local Muslim leaders in New Mexico have cautioned against characterising the killings as motivated by sectarianism. They have expressed fears that an oversimplification of the situation could lead to distrust among Shia and Sunni communities, who pray together at the Islamic Center of New Mexico, Albuquerque’s main mosque.
People who knew both the victims and Syed have said the killings were likely connected more to personal feuds or revenge.
Investigators, while not yet determining a motive, have previously said “an interpersonal conflict” may have led to the violence.
Syed’s son Shaheen also remains in federal custody on charges he provided false information to investigators about the guns and vehicle used in the attacks.