For days, the news that someone might be killing Muslim men in Albuquerquespread fear among the city’s Muslim residents, some of whom were so afraid of becoming the next target that they fled town or hunkereddown in their homes.

On Tuesday, the police said they had arrested a man who was himself Muslim and who may have targeted at least two of the victims because he was angry that his daughter had married a man from the other major branch of Islam.

The police said the man, Muhammad Syed, 51, would be charged in two of the killingsand that he was a suspect in the other two deaths.

Ahmad Assed, the presidentof the Islamic Center of New Mexico, a mosque that at least three of the victims had attended, said he understoodthat the authorities were looking at the possibility that the suspect was a Sunni whomay have been motivated by resentment over marriage to a Shia.He and the police cautionedthat details remained sparse.

Police officials said they were not yet sure if a dispute over marriage was the sole motive, but said they were aware of it and had found evidencethat an “interpersonal conflict” may have led to the shootings.Chief Harold Medina of the Albuquerque Police Departmentsaid that it was not yet appropriate to label the killings as either hate crimes or serial murders.