Authorities don't believe the suspected shooter knew the victim, Ahmed Al-Jumaili, Dallas Police Maj. Jeff Cotner said reporters, nor do they believe he knew Al-Jumaili's ethnicity.
And they haven't given any indication Al-Jumaili had anything to do with what led the teen to head out armed in the first place -- a purported shooting at his girlfriend's apartment, if that in fact happened. Cotner said that, while there have nearby shootings that might be tied to gangs, "we (have been) unable to substantiate ... whether or not there was an actual shooting at the apartment."
What police do believe, based on witness testimony and other evidence, is that the teenager shot and killed Al-Jumaili, for whatever reason.
"When he saw Mr. Al-Jumaili and their family, he targeted them, he shot at them with intent," Cotner said of the suspect, who is under arrest. "And as Mr. Al-Jumaili ran back toward his apartment, he tracked him with his rifle and continued to fire."
Dallas police named the suspected shooter, though CNN is not identifying him yet since he's a minor and it's not clear if he'll be charged as an adult. The teen turns 18 in May, police said.
From playing in snow to downed by gunfire
Until the fatal shots ended Al-Jumalli's life, March 4 had been a day of fun and joy for Al-Jumaili and his family.
The 36-year-old, who had immigrated to the United States 20 days earlier, joined his brother and wife taking pictures in the parking lot of a Dallas apartment complex amid the snow.
"Just like all of us, a pretty snowfall brings the child out in us," Cotner said.
Then came the gunshots and Al-Jumaili's cry, "I'm hit!"
A few hours later, the Iraqi immigrant was dead.
Three days later, a Dallas detective found surveillance footage from a nearby elementary school showing four people coming from the apartment complex. The black-and-white soundless surveillance video
shows one person apparently carrying a rifle is seen running just ahead of a second person seemingly carrying a hand gun, Dallas police Officer Monica Cordova said.
Approximately 13 seconds later, another person comes into view and passes by the camera, followed by a fourth individual who is walking, she said.
Then, on Tuesday, a witness walked into the Richardson, Texas, police station and provided a nickname of a possible suspect -- Kaca.
Police: Suspect changed his story
That nickname eventually led to the 17-year-old police believe shot Al-Jumaili.
Investigators interviewed him for the first time Thursday, at which time he denied ever leaving his girlfriend's apartment. Then, authorities got the OK to search his apartment and found an unfired rifle cartridge, Cotner said.
The teen was brought to Dallas police headquarters for another interview, and he changed his story. Yes, he had been at the scene of Al-Jumaili's killing. But no, he hadn't done it.
Yet that's not what someone who'd been with him said. According to Cotner, this witness said he saw Al-Jumaili taking pictures in the snow,
"The witness stated that he observed (the suspect) raise the rifle," the police major said. "... The witness then heard one shot, followed by several more."
Then all of them bolted.
Advocate: High hate crime awareness among Muslims
The incident caused waves in Dallas' Muslim community. While police haven't given any indication this was a hate crime, though Alia Salem -- executive director of the Council on American-Islamic Relations
in the Dallas and Fort Worth area -- noted "a heightened sense of awareness with regard to hate crimes against Muslims."
Speaking Friday on behalf of Al-Jumaili's family, Salem expressed gratitude to police and others for their work on the case and said "our community has been at a loss for words and very saddened by this tragic death."
"We just want to see justice happen here," she said. "And this is the first step in that."