A man questioned as a "person of interest" in connection with a series of shootings along a Phoenix freeway is not a suspect, authorities said Saturday.
It appeared Friday that police might have a break in the spate of at least 11 shootings on or near Interstate 10 over the past two weeks when they detained the 19-year-old local man who was questioned.
The man was booked on an unrelated possession of marijuana charge. He was ordered held without bond Saturday because authorities say he has an outstanding warrant for parole violation, The Associated Press reported.
"It’s frustrating, but you’ve got to remember it’s a very difficult case to investigate," Arizona Department of Public Safety public information officer Bart Graves said. "There’s a lot of moving parts."
Graves told reporters Friday that investigators were "asking him about a number of things," including the I-10 shootings. Authorities have declined to say what led them to detain the man, citing the ongoing investigation.
NBC News is not reporting the name of the "person of interest" unless he is identified as a suspect or more definitively tied to any of the shootings.
As the man was led away by police Friday, a reporter asked him if he knew anything about the shootings, and he said, "No."
The shootings have Phoenix drivers on edge. Two drivers reported shattered glass on Saturday, but both incidents were determined to be road debris and unrelated to the shootings, Arizona Department of Public Safety Trooper Tim Case told reporters.
Police are warning that people should continue to stay alert. Traffic is expected to be heavy in the Phoenix area Sunday when the Arizona Cardinals football team takes on the New Orleans Saints in a home game Sunday.
"We need the ongoing support, vigilance and patience of our community and the media as this is a very complex and ongoing investigation," said Arizona Department of Public Safety Director Col. Frank Milstead said in a statement Saturday.
Milstead said Wednesday that the shootings might have been carried out by different people "just because the M.O.'s have changed."
Eight of the incidents involved bullets, while three others involved what have been called "projectiles." The only person who has been injured in the violence was a 13-year-old girl who was cut by flying glass.
There have been no related incidents since Thursday, Case said.
"Just stay vigilant, keep your eyes open, anything you see that’s out of the ordinary call us or email us," Case said.