Joseph DeAngelo, the man now known as the "Golden State Killer," addressed the court on Friday as he was sentenced to life in prison without parole.
DeAngelo, who had sat in a wheelchair and was covered by a white face mask as victims and family members gave statements, rose out of the wheelchair and spoke free of the face covering.
"I've listened to all your statements. Each one of them," DeAngelo said. "And I'm truly sorry to everyone I have hurt. Thank you, your honor."
DeAngelo, who was a police officer from 1973 to 1979, committed 13 murders as well as multiple rapes and burglaries in the 1970s and '80s. Now a 74-year-old father and grandfather, DeAngelo was arrested in 2018.
In June, he pleaded guilty to 13 counts of first-degree murder as part of a plea deal, which also required him to admit to multiple uncharged acts, including rapes.
The death penalty was taken off the table in exchange for the guilty pleas.
"I honestly believe that this person -- not even a person, this beast -- deserved the ultimate punishment of death," Orange County District Attorney Todd Spitzer said Friday. "But we met with our victims. We knew the age of the case. We knew how long it took to solve. And we knew that this was the right thing to do."
"For the victims whose voices have been stolen and the family members who sadly ran out of time and could not make it here today, I want you to know that there are 13 angels watching us today," Spitzer said.
Sacramento County District Attorney Anne Marie Schubert added, "My greatest hope for all of these victims and their families perhaps is best put in their own words as we heard this week. The greatest revenge is to live your lives. Paint your children's and your grandchildren's rooms again with hearts and rainbows. Water ski again. Know that the monster of your childhood or your younger years is gone forever and will die alone in the dark."
A statement from DeAngelo's sister, which was read in court Friday, put some blame on their father who she described as an abuser and a womanizer. A statement from DeAngelo's niece described him as a loving and patient man who taught her how to drive.
This week brought three days of victim and family impact statements, beginning Tuesday and Wednesday with powerful words from rape survivors and their relatives. On Thursday, DeAngelo was confronted by the family members of people he murdered decades ago.
"His crimes were always committed in the dark of night. And it was common for him to cover lights," said Ventura County District Attorney Gregory Totten. "Even now here in this courtroom he turns away from the light, and dare not face or look at his accusers, for fear that the truth of their testimonies might penetrate the deep darkness."
'I was the only living witness'
On Sept. 11, 1975, DeAngelo, who was a police officer at the time, shot and killed journalism professor Claude Snelling in front of his daughter, Elizabeth, at their Visalia, California, home.
"My father caught him twice peering in my bedroom window when he came home from teaching night school, and tried to chase him down but wasn't able to catch him," Elizabeth Snelling said in court Thursday.
In the early hours of Sept. 11, Elizabeth Snelling, who was 16 years old, said she was awakened by an intruder in a ski mask who pointed a gun at her head.
Snelling said the intruder told her "he was taking me with him and if I made any noise he would kill me."
DeAngelo dragged her out of the house with a gun pointed at her head, she said, and her dad charged out of the house.
"DeAngelo fired two shots hitting my dad," she told the court. "He then turned the gun on me as I was down on the ground. My only thought was, 'this is it.'"
"He started kicking me in the head and face, then ran off," she said.
Claude Snelling was 45 years old and in "the prime of his life," his daughter said, calling him her "hero."
"We somehow managed to stay in the same house, but with added security. I slept in my mom's room for the next year," Elizabeth Snelling said.
"Knowing that my dad's murderer was never caught ... left us all feeling very vulnerable," she continued. "Since I was the only living witness ... there was a chance he could come after me. The police gave us extra security and patrolled our neighborhood ... but I still lived in fear."
"DeAngelo was able to live a normal life with his family for all those years while my family and I could not be with my dad," she said. "I am so thankful that he will at least spend the rest of his miserable life in prison."
In March 1980, Charlene Smith and her husband, attorney Lyman Smith, were killed in their Ventura home. The couple was found dead by Lyman Smith's 12-year-old son, Gary.
"The walls were splattered with blood and gray matter. The bed was saturated with bodily fluids," Lyman Smith's daughter, Jennifer Carole, said Thursday. "Gary gently lifted the corner of the comforter to find my dad face down in the pillow cemented to the fabric by blood."
Carole was 18 at the time of the murder.
"Joe might be surprised to learn that I was a suspect for two days," Carole said to DeAngelo in court, as he sat silently.
"I've lived with the shame for decades," Carole said, crying. "It's your shame, Joe."
"Joe sitting here [in court] with his blank face, [trying] to ignore what he's done to not validate his victims ... is not justice," Carole said. "Joe spending the rest of his life in prison is not justice. ... Justice is not possible in this case."
"It's been a never-ending ache and sadness that does not go away," Charlene's best friend, Jill-Karen Morrill, said in court. "Charlene was so much more than beautiful and Lyman so much more than handsome. When she and Lyman were taken, the world lost two amazing people, full of life and both with bright futures."
"I cannot allow myself to think of all they endured in death. But we know of the unspeakable horror they suffered," she said.
'If I had my way he would be shivering, blindfolded, naked and exposed'
In July 1981, Cheri Domingo and her boyfriend Gregory Sanchez were killed.
Sanchez, 27, was shot and bludgeoned in the head two dozen times, prosecutors said. DeAngelo then bound 35-year-old Domingo, raped her and beat her in the head more than 10 times, prosecutors said.
"My heart is racing," said Domingo's daughter, Debbi McMullan, as she began speaking in court Thursday.
McMullan, who was 15 at the time of her mother's murder, said in her 20s, "I started to sink into a depression that was undiagnosed and untreated for many years."
She said she "stumbled into drug use," during which "a decade was lost."
"Mom would have helped," she said. "She would have supported me and guided me toward solutions. She would have prodded me into admitting that I needed help."
By her mid-30s, McMullan was clean, sober and welcoming her children back home, she said. McMullan then learned her mother's slaying may be the work of a serial killer and she poured her energy into helping solve the case.
"I am not that lost teenager anymore. Today I am in the room with the pathetic excuse of a man who will now finally be held accountable," she said. "If I had my way he would be shivering, blindfolded, naked and exposed every moment from now on."
'He had no idea how much Katie and Brian were loved'
In Feb. 1978, Brian and Katie Maggiore were shot dead while walking their dog. After Brian Maggiore was shot, his wife ran away and yelled for help, but DeAngelo caught up with her and shot her in the head, prosecutors said.
Katie turned 20 years old four days before she was killed in "cold blood," her brother said in court Thursday.
"He had no idea how much Katie and Brian were loved. They have remained alive in all our hearts," he said.
'I hope he rots'
In May 1986, 18-year-old Janelle Cruz was bound, raped and bludgeoned in the face and head, prosecutors said.
Cruz's sister, Michelle Cruz, said in court, "I wonder if [DeAngelo] remembers the details. I wonder if he remembers Janelle, my sister, fighting him off."
She was beaten "beyond recognition" and needed a closed casket funeral, Cruz said.
"My sister had a lot of hard times growing up, but she was finally on a good path. She had dreams of going to college, living in her first apartment, getting married, having children," Cruz said, noting that DeAngelo had a "good, full life" with a wife, children and a home.
"I cry for her all the time," she said. "I wonder if Joseph DeAngelo has any remorse."
After her death, "I lost my identity," Cruz said, and she devoted her life to finding her sister's killer.
When DeAngelo was arrested, Cruz said she "cried and cried for hours."
"I could stop looking over my shoulder with fears of him sneaking up on me," Cruz said. "No more thinking he would try and find and kill me, too. I did not have to keep moving house to house -- all the things that haunted my mind for 32 years."
"I hope he rots," she said.
'Black and soulless eyes'
In Feb. 1981, 28-year-old Manuela Witthuhn was bound, raped and bludgeoned to death while home alone.
Manuela Witthuhn's husband David suffered extreme grief, anxiety and depression for years, said his brother, Drew Witthuhn.
Drew Witthuhn shared with the court a photo of Manuela's headstone, a place he said David often visited to be near her.
For years, Manuela's husband lived with "scrutiny and suspicion" that he may have been involved in the slaying, Drew Witthuhn said. DNA later proved it was a serial killer, but David died before DeAngelo was identified, his brother said.
Drew Witthuhn only referred to DeAngelo as "the convict," and remarked that he has "black and soulless eyes."
'Her future was stolen'
Debra Manning and her boyfriend, Robert Offerman, were killed on Dec. 30, 1979.
Manning was bound, raped and shot twice in the head, while Offerman was bludgeoned and shot four times, her friends said in a statement.
"Her future was stolen," they said.
'DNA may have stopped the 'Golden State Killer'
In August 1980, Keith Harrington, a medical school student, and his wife Patrice Harrington, a pediatric nurse, were bludgeoned to death in their Dana Point home. They had been married for three months.
"Our dad found them two days later," said one of Keith Harrington's older brothers, Ron. "Dad was never the same."
The Harringtons devoted their lives to looking for the killer, but their father died before they had an answer.
The brothers' advocacy continued, pushing for an expanded DNA database in California.
"If these crimes had occurred today, DNA may have stopped the 'Golden State Killer' before he progressed to murder," Ron said in court.
DeAngelo was the first public arrest obtained through genetic genealogy, a new technique that takes the DNA of an unknown suspect left behind at a crime scene and identifies him or her by tracing a family tree through his or her family members, who voluntarily submit their DNA to public genealogy databases.
To identify DeAngelo, investigators narrowed the family tree search based on age, location and other characteristics. Authorities conducted surveillance on DeAngelo and collected his DNA from a tissue left in a trash. Investigators plugged his discarded DNA back into the genealogy database and found a match, linking DeAngelo's DNA to the DNA found at multiple crime scenes, prosecutors said.
Since DeAngelo's April 2018 arrest, over 150 other crime suspects have been identified through genetic genealogy.
ABC News' Jenna Harrison contributed to this report.