By Lisa Maria Garza

(Reuters) - Dallas police arrested a teenager in last week's fatal shooting of an Iraqi immigrant who was gunned down while taking pictures of his first snowfall, officials said on Friday.

Police said they do not see the killing as a hate crime. Ahmed al-Jumaili, 36, had only been in the United States for about three weeks to be reunited with his wife when he was shot in the chest as he stood in the parking lot with his family, enjoying the snow, according to police.

Al-Jumaili ran into his apartment and collapsed. He was pronounced dead later at an area hospital. Investigators found 15 bullet casings at the crime scene.

Nykerion Nealon, 17, was charged with murder in his death. Police said Nealon appears to have been trying to retaliate for a separate shooting that took place at his girlfriend's apartment.

"We don't believe that he knew Mr. al-Jumaili. We do not believe that he knew Mr. al-Jumaili's ethnicity," police spokesman Major Jeff Cotner said at a news conference.

Surveillance video released by police showed four men running away from a nearby apartment complex, with one man carrying a rifle.

More arrests are possible as police investigate whether the other three men in the video are at fault in the shooting death, Cotner said.

The possibility that al-Jumaili might have been targeted put Muslims on edge, said Alia Salem, executive director of the Dallas-Fort Worth chapter of the Council on American-Islamic Relations, which has offered a $12,000 reward for information that identified the killer.

(Aditional reporting by Marice Richter)