Phoenix Mayor Greg Stanton joined law enforcement authorities Thursday to implore the community for any possible tips on the still-at-large serial shooter.
Authorities said there have been no known incidents since the last confirmed shooting in July, and say the shooter is not confined to one part of the Valley.
The reward for information leading to the suspect’s arrest has been increased to $75,000.
Officials from the FBI and the U.S. Marshal Service were also at the news conference.
"We also know that serial killers like to brag about the atrocities that they commit," U.S. Marshal David Gonzales said. "We don't think that this is any different."
Dubbed the "Serial Street Shooter," by police, the gunman is suspected of killing seven and wounding two in nine drive-by attacks since March. Most of the incidents took place at night as the victim was standing or sitting in a car outside a home. They occurred in two mostly Hispanic, working-class areas. In most of the cases, witnesses did not get a good look at the suspect's face or the vehicle leaving the scene.
Maricopa County Attorney Bill Montgomery said anyone with information can remain anonymous, and should not fear retribution based on his or her immigration status.
“Anyone who comes forward to assist with this case whether a witness or a victim, their immigration status will not be considered whatsoever. And I will not accept for charging any case that arises out of someone’s immigration status that was revealed as a consequence of this investigation," said Montgomery.
Authorities say more than 1,500 tips have come in and been investigated so far.
Associated Press contributed to this report.
