Three teenagers have been arrested over at least a dozen slingshot attacks in the Phoenix-area in what authorities described Sunday as a copycat spree mimicking the freeway shootings that have terrorized drivers for three weeks.
Asked whether the arrests marked a resolution to the investigation of 11 shootings of vehicles on Interstate 10 since late August, Bart Graves, a spokesman for the state Department of Public Safety, told NBC station KPNX of Phoenix: "God, no. I can tell you that for sure."
The three suspects — identified as Aaron Nottingham, Albert German and Christian Cook, all 18 and all of Mesa — were held on charges after the driver's-side window of a vehicle was shattered by a projectile Saturday, Maricopa County Sheriff Joe Arpaio told reporters.
Another individual, who wasn't identified but is also 18, was under investigation Sunday, the sheriff's office said.
The driver and his wife managed to record the license plate number of the attacker's vehicle, which pulled alongside them on a surface street leading to Mesa Gateway Airport, said Col. Frank Milstead, the state director of public safety.
The suspects admitted having shot granite projectiles with a slingshot at at least a half-dozen pedestrians and seven vehicles during a short period late Saturday, he said.
Milstead and Arpaio stressed that the arrests appeared to be unrelated to the string of 11 serial shootings on Interstate 10.
Still, "none of this is fun and games," Milstead said. "This is very serious."
He said his message to other would-be copycats is to heed the consequences for Saturday's suspects: "They're all in jail, and they've probably impacted their life negatively for some time to come, because now they will all end up with criminal records."
The most recent shooting in the spree, which began on Aug. 29, was reported Thursday morning and involved a bullet strike on a commercial truck-tractor, but it isn't clear when the vehicle was struck, police said.
Eight of the shootings have involved bullets, while three other vehicles were hit with unspecified projectiles, the Public Safety Department said.
The drivers of the struck vehicles have escaped the violence uninjured, but a 13-year-old girl was cut by flying glass in one incident, according to police.
Phoenix drivers who fear they might not be so lucky have avoided the highway while investigators work to find a suspect or suspects tied to the crimes, and determine whether they are all related.
Col. Frank Milstead, the state director of public safety, said Wednesday that he believes multiple people are behind the spree "just because the M.O.'s have changed."
Authorities offered a $20,000 reward for information leading to any suspects, and Gov. Doug Ducey appealed Thursday to the public for help.