New details emerge from deadly shooting at Des Moines high school

• Three vehicles initially drove past the group and then returned a second time, closely behind one another. Multiple shots were fired at the group from inside the cars, which then drove off, according to the filings.
• Around 20 spent shell casings were found at the scene and 15 more were later found from the vehicles, per the court documents.

Plus: Detectives were "very familiar" with the three vehicles, Sgt. Paul Parizek, spokesperson for DMPD, told Axios. Police traced them back to a home in the 1800 block of 23rd Street.

• Police also obtained security footage from near the home, which captured the three vehicles leaving from before the shooting and returning right after, according to court documents.

The latest: Police on Tuesday named Jose David Lopez as the 15-year-old victim who was killed. He was not a student in the Des Moines school district.

What they're saying: Parizek said it's unclear why the teens were gathered outside at the time of the shooting.

• He said that while the shooting happened at a school, it was not a "school shooting," adding that Lopez was targeted by the suspects.
• "It could have just as easily happened at 2:48 in the morning at somebody's house," he said.

The bottom line: The footage helped identify the people in the cars and subsequent interviews led to the arrests of six teens, who are facing murder charges.