Police connected Saucedo to the actions of the so-called Serial Street Shooter, whose victims seemed to be chosen at random.
A "wide host of evidence" linked Saucedo to the series of shootings, including ballistics, surveillance, witnesses and other forensic evidence, Howard said. On 12 June, Stefanie Ellis, 33, her daughter Maleah, 12, and family friend Angela Linner, 31, were shot as they listened to music in a vehicle.
Aaron Saucedo was arrested for a fatal shooting in April, but. has since been re-booked in connection with another 26 charges in connection with shootings from March until July of 2016.
The three incidents there were added to the serial killer case happened before the original first shooting, which was on March 17, 2016.
It was not clear Monday whether Saucedo had obtained a lawyer.
"I'm innocent" were the only other words he spoke during the appearance before a judge who agreed with a prosecutor that that Saucedo should be held without bond.
Police arrested Saucdeo in that case after finding a pistol he'd sold at a pawn shop and matching it to evidence found at the crime scene, court documents said.
Maricopa County Attorney's Office spokeswoman Amanda Jacinto says she couldn't immediately provide any information.
The investigation into the serial killings had focused what authorities said were seven fatal shootings.
The 2015 victim was a 61-year-old man who had dated the suspect's mother, Phoenix Police Chief Jeri Williams said.
Speaking to PEOPLE Tuesday morning, Phoenix police spokesman Jonathan Howard likens the year-long investigation that led to 23-year-old Aaron Saucedo's arrest to assembling a jigsaw puzzle. Romero had been dating Saucedo's mother at the time of his death.
Police have identified new victims in a series of Phoenix shootings that resulted in the arrest of a 23-year-old man.
The announcement on Monday came, after police received 3,300 tips from members of the public, and Silent Witness will pay $75,000 in reward money.
Saucedo, who has been in custody since April, pleaded not guilty to that charge.
The Associated Press was unable to reach Saucedo's public defender on Monday. Since that time, Saucedo has been implicated in the death of 22-year-old Jesse Olivas, who was killed in a drive-by shooting on January 1, 2016.
The suspect then went on a killing spree from March of previous year through July, police said.
Nine people were killed in all in a case dubbed the Serial Street Shooter.
He is later believed to have fired at random on complete strangers in the street, killing eight people.
"We hope that our community will rest a little easier and that our officers will get a little more sleep knowing that the wheels of justice are finally in motion", she said.
Nobody was killed in those shootings, in which about a dozen vehicles on the interstate outside the city were shot between August 29 and September 10. "We can't bring my brother back", said Hosanna Lopez, who is the victim's sister.