ALBUQUERQUE • A fear of attacks that had rippled through Muslim communities nationwide after the fatal shootings of four men in Albuquerque gave way to shock and sadness when it turned out the suspect in the killings was himself a Muslim.

Muhammad Syed, 51, of Albuquerque was arrested Monday after a traffic stop more than 100 miles from his Albuquerque home. The Afghan immigrant denied connection to the crimes that shook the city and its small Muslim community.

In court documents, in fact, he told police that he was so unnerved by the slayings that he was driving to Houston to find a new home for his family.

But investigators say they have ample evidence to prove his guilt, though they have yet to uncover the motive. The first ambush-style shooting happened in November and was followed by three more between July 26 and Aug. 5.

According to the criminal complaint, police determined that bullet casings found in Syed’s vehicle matched the caliber of the weapons believed to have been used in two of the killings and that casings found at the crime scenes were linked to guns found at Syed’s home and in his vehicle.

Of the more than 200 tips police received, it was one from the Muslim community that led them to the Syed family, authorities said.