The suspected "Golden State Killer" appeared in a Sacramento County, California, court for the first time since he was arrested.
Former police officer Joseph James DeAngelo, 72, donned an orange jumpsuit and handcuffs as he was wheeled into the courtroom for his arraignment. He appeared to be weak and frail and was surrounded by five police officers.
He did not enter a plea.
DeAngelo spoke twice during the hearing -- when he was asked to state his name and whether he had an attorney.
"I have a lawyer," he replied in a raspy voice.
He was denied bail, according to The Associated Press.
Tissues were passed around among emotional audience members in the front row of the courtroom, who appeared to be members of the victims' families.
When one attendee was asked by reporters how she felt to see DeAngelo in court, she replied that he looked like "an old man."
"I feel like justice is starting," she said.
DeAngelo was taken into custody Tuesday at his home in Citrus Heights, a city in Sacramento County. He lived at the home with his family but was alone when he was arrested, authorities said.
The suspected killer's alleged crime spree began in Sacramento County in 1976 and continued down the Golden State coast until 1986.
DeAngelo allegedly committed 12 murders as well as 50 rapes and multiple home burglaries in the 1970s and 1980s.
His name came up for the first time in the investigation to catch the notorious killer last week, Sacramento District Attorney Anne Marie Schubert said. DeAngelo was then surveilled, and DNA from an item of his that police had collected was confirmed as a match.
Investigators trying to hunt down the "Golden State Killer" had misidentified an elderly Oregon man as a possible suspect after using information from genetic websites, The Associated Press reported.
Authorities cited a rare genetic marker, which the Oregon man shared with the killer, to convince the judge to issue an order that the 73-year-old provide a DNA sample, according to the AP.
Investigators had used a genetic profile based on DNA from the crime scene linked to the "killer and compared it to information from genealogical websites," the AP reported. They then created a family tree and used public records to identify the man whom they wrongly accused.
DeAngelo served in the Navy in the 1960s and was a police officer in the 1970s. He was fired from his post in the city of Auburn in 1979 for allegedly stealing a hammer and a can of dog repellent, according to the AP, which cited articles from the Auburn Journal at the time.
He then spent 27 years working at a distribution center for Save Mart Supermarkets in Roseville, near Sacramento, and retired last year, according to a spokesperson for Save Mart.
DeAngelo's next court appearance is scheduled for May 14 at 8:30 a.m.
ABC News' Jennifer Harrison and Emily Shapiro contributed to this report.