Last Updated Aug 10, 2016 3:13 PM EDT
LOS ANGELES -- A serial killer known as the "Grim Sleeper" was sentenced to death Wednesday for the murders of nine women and a teenage girl that went unsolved for years as the body count grew in a poor section of Los Angeles haunted by the scourge of crack cocaine.
Lonnie Franklin Jr. was sentenced in Los Angeles County Superior Court after emotional family members of his victims spoke about the pain they had endured for decades.
"I can't think of anyone I've encountered in all my years in the criminal justice system that has committed the monstrous crimes that you have," Judge Kathleen Kennedy told Franklin.
The killings occurred over more than two decades during the crack epidemic, and community members complained that police didn't seriously investigate because the victims were black and poor and many were drug users and prostitutes.
Franklin, 63, a former trash collector and onetime garage attendant for Los Angeles police, denied any role in the killings to investigators but didn't utter a word in his defense during his lengthy trial.
Prosecutors connected him to the crimes through DNA, ballistics, photos and the words of the sole known survivor, who managed to get away after being shot. A Polaroid photo of her partly nude and bleeding from her wound was found in Franklin's garage after his arrest.
Nearly three decades after the attack, the survivor, Enietra Washington, pointed out her assailant in court, saying, "That's the person who shot me."
Deputy District Attorney Beth Silverman said Franklin's motive was "doing evil," and his "degrading, calculated and brutal" crimes had destroyed many lives.
"This defendant is completely irredeemable," Silverman wrote in her sentencing brief. "He is a psychopathic, sadistic serial killer who takes joy in inflicting pain on women and killing them."
Franklin's attorneys had suggested a mystery man was the real killer and asked jurors to spare the defendant's life.
Defense lawyer Seymour Amster said in court filings that the death verdict should be set aside because prosecutors introduced evidence that Franklin killed four other women, though he was never charged with those crimes.
Amster also asked for a new trial because he said Silverman engaged in prosecutorial misconduct by rolling her eyes in a way that mocked the defense in front of the jury and elicited snickers from family members of the victims.
Silverman said they were unsubstantiated allegations and accused Amster of bullying tactics, name-calling and dishonesty.
Petty sniping and name calling between Amster and Silverman were on display long before the jury was seated and continued throughout the long-running case.
The exasperated judge said the two seemed to have a vendetta against each other and she feared World War III would break out in her courtroom.
"I want you to stop it," she blurted at one point. "I'm sick and tired of it."
Franklin sat upright and attentive throughout the trial, rarely speaking with his lawyers and showing no emotion as the verdicts were read. None of his family showed up in court.
He was convicted of killing seven women between 1985 and 1988 and the 15-year-old girl and two women between 2002 and 2007. Most of the women were fatally shot at close range, though two were strangled and two were shot and choked.
The killer earned his moniker because of the apparent hiatus, which police once theorized was due to being imprisoned or laying low.
Now, though, authorities say they don't think he ever rested and may have committed far more than the 14 killings they outlined in court, which included the four deaths he wasn't charged with committing.
When a task force re-examined the old cases following the 2007 killing, DNA from Franklin's son showed similarities to genetic evidence found on some of the victims.
A detective posing as a busboy at a pizza parlor collected utensils and crusts while Franklin was attending a birthday party. Lab results connected him to some of the bodies and led to his arrest.
Though Franklin was sentenced to death, no one has been executed in California since 2006, and the state is involved in ongoing legal battles related to the death penalty, according to the Los Angeles Times. More than 700 inmates are currently on the state's death row.