Update 8.17pm: A former bus driver arrested over a string of killings that terrorised several neighbourhoods of Phoenix, Arizona, has declared "I'm innocent" during a brief court hearing.
Aaron Saucedo appeared before a judge and acknowledged that he understood the purpose of the court appearance to inform him of the allegations.
"I'm innocent" were the only other words Saucedo said during the appearance before the judge, who agreed with a prosecutor that he should be held without bond.
A man has been arrested in connection with a series of shooting attacks in the US that left nine people dead.
Phoenix police announced that 23-year-old Aaron Juan Saucedo was taken into custody in connection with the case that authorities said was the work of a serial killer.
For more than a year, police were stumped by the string of killings in which a shooter stalked victims after dark and gunned them down as they stood outside their homes or sat in their cars.
Officers fielded thousands of tips, went door-to-door in Phoenix and analysed ballistics from a different, unrelated serial shooting case.
Yesterday, they announced they had arrested Saucedo, a former city bus driver, over the killings while providing scant detail about what motivated him or details about how they made a break in the case, other than to credit tips.
Saucedo faces 26 felony counts of homicide, aggravated assault and drive-by-shooting for 12 shootings that took place between August 2015 and July 2016, Phoenix Police Chief Jeri Williams said.
The investigation into the serial killings had focused on what authorities said were seven fatal shootings.
However, police said on Monday they had tied Saucedo to nine killings in all - eight random victims and one man that he knew.
Saucedo was a bus driver for the city of Phoenix through a temp agency for several months in July through August 2015, Phoenix police said.
Records show Saucedo was pulled over for allegedly running a red light on October 27 2015, just a month after the first killing.
On Monday, Ms Williams and Mayor Greg Stanton appeared alongside other top officials, including Maricopa County's top prosecutor, to announce the break in a case that had appeared largely stalled in recent months as leads and tips dried up.
"This case plagued our community for more than a year... and left behind a trail of victims that included mothers, sons, brothers, sisters and families still mourning the loss of their loved ones," Ms Williams said.
Police say they do not know what motivated Saucedo and that he did not have any connection to eight of the people who were killed.
They said they would be giving out the US$75,000 (€68,442) reward offered for tips, but they would not reveal details about whether the money was going to one person or multiple people.
The case finally broke when Saucedo was arrested last month in connection with the August 2015 fatal shooting of a man, 61-year-old Raul Romero, who had a relationship with Saucedo's mother.
Authorities investigated Saucedo more closely and connected him to the serial killings.
Police say that after Romero's killing, Saucedo struck again about four months later in killing 22-year-old Jesse Olivas, who was gunned down on New Year's Day 2016 while standing in front of a home.
The suspect then went on a killing spree from March of last year until July, police said.
In the end, nine people were killed in 12 separate shootings.
All of the killings were random except for the first one, Ms Williams said.
"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.
Gisela Castro, the mother of shooting victim Manuel Castro-Garcia, said news of the arrest felt like she was reliving the day she was told her son had been killed.
Mr Castro-Garcia, 19, was fatally shot on June 10 2016.
"For one part I'm happy because there's going to be justice in my son's death and others' deaths and that person is not gonna do more damage.
"But my son is not coming back," Ms Castro said.
"I waited every day for justice, but things don't change. The pain is the same."
Ms Castro said her son was a noble person who studied and worked hard and was loved by everyone he knew.
She said he was never a trouble-maker and preferred playing basketball with friends over partying.
"The only thing I can say is thank God there's going to be justice and we leave it in God's hands.
"May God bless (Saucedo), and I'm not anybody to wish bad upon him," she said.
Marina Smith, the partner of 21-year-old Diego Verdugo-Sanchez, who was gunned down on April 1 2016, said she welcomed news of the arrest but was still struggling with his loss.
She was seven months pregnant with the couple's child when Mr Verdugo-Sanchez was fatally shot in front of a home.
Ms Smith said she had grown frustrated over the past year as detectives kept her in the dark about the investigation.
"The fact of them finding somebody, at least it was some type of news," she said.
Police say Saucedo shot at two teenage boys on March 17 2016, striking one of them in the arm.
The suspect struck again the next day but did not kill anyone.
The next shooting did not happen until April 1 2016, when Mr Verdugo-Sanchez was fatally shot.
Police also have linked Saucedo to the April 19 2016 death of 60-year-old Krystal White; the June 3 2016 death of Horacio de Jesus Pena; and to the killings of two women, Angela Linner and Stefanie Ellis, and 12-year-old girl Maleah Ellis on June 12 2016.
He killed Manny Castro Garcia on June 10 2016, police said.
In the most recent attack on July 11 2016, a 21-year-old man and his four-year-old nephew escaped injury after the gunman shot at a vehicle they were sitting in.