L.A. Mayor: Grim Sleeper 'terror has finally come to an end'

(CNN) -- The arrest of a suspect in the Grim Sleeper serial killings ends a quarter-century of "terror" for Los Angeles, the city's mayor said Thursday.

Lonnie David Franklin Jr., 57, made his first appearance Thursday in Los Angeles Superior Court on murder and attempted murder charges. He was ordered held without bail pending an arraignment scheduled for August 9.

"For the last 25 years, one man preyed on the innocent and stole the lives of women living in some of our toughest neighborhoods," Mayor Antonio Villaraigosa told reporters Thursday.

"Today, I'm proud to announce that this terror has finally come to an end," he added.

Nicknamed for taking long breaks between attacks, the Grim Sleeper is believed responsible for at least 11 deaths since 1985 in south Los Angeles. The killer targeted black women, some working as prostitutes, using the same small caliber weapon. The police had DNA of the killer for years, but no one to match it.

Villaraigosa, Los Angeles Police Chief Charlie Beck and California Attorney General Jerry Brown praised police for the arrest at a news conference Thursday. Authorities said a DNA match from a database Brown championed tied Franklin to the killings, and the attorney general said the case demonstrates the value of the sometimes-controversial tool.

Brown said California's familial DNA search program led to the identification and arrest of Franklin.

The program -- which was enacted in 2008 against opposition from civil rights groups -- uses the DNA of family members to find suspects in cases of great risk to the public, Brown's office said in a press release.

"We're going to fight to protect this technology, and next week my office will be in court defending another form of DNA technology," said Brown, a former governor now running for the office again.

Using the DNA of one of Franklin's family members, who had been convicted of a felony weapons charge, investigators established a familial connection between the family member and DNA collected at the murder scenes, the statement said. That connection was used to identify and arrest Franklin after his DNA was obtained.

"This arrest provides proof positive that familial DNA searches must be a part of law enforcement's crime-fighting arsenal. Although the adoption of this new state policy was unprecedented and controversial, in certain cases, it is the only way to bring a dangerous killer to justice," Brown said.

Los Angeles District Attorney Steve Cooley said detectives then used a piece of discarded pizza with Franklin's DNA to make the link, according to CNN affiliate KTLA.

Examine CNN's interactive evidence case file on the Grim Sleeper

One of the Grim Sleeper's victims was Alicia Alexander, 18, who was killed in September 1988. She left her home in South Central Los Angeles to run to a nearby store and disappeared. Her body was found four days later. Police said she was sexually assaulted and shot once in the chest.

Overcome with emotion, Alexander's father Porter Alexander reacted on Wednesday.

"It just -- it was such a good relief," he said.

Franklin is a former city trash collector who at one time worked as a garage attendant at an LAPD station. His arrest came as a shock to neighbors, KTLA reported.

Margaret Prescod, who founded the Black Coalition Fighting Back Serial Murders and worked with the families of victims in the case, said the Grim Sleeper Task Force informed her of the arrest Wednesday.

Prescod said Det. Dennis Kilcoyne, head of the task force, told her that unlike a previous arrest in the case that turned out to be wrong, he was sure they had gotten their man this time.

"He told me that what they have is very solid," Prescod said.

Prescod said she is "cautiously optimistic" because an arrest years ago in the case, which police touted as solidly based on ballistics evidence, turned out to be false.

If Franklin turns out to be the Grim Sleeper, "It would be a huge relief, not only for the [victims' families], but for the entire community that remained at threat," Prescod said.

"We are mortified that it has taken this long to make an arrest, but nevertheless, one is always glad when there is a breakthrough and we can only hope right now that it is a solid breakthrough."

Prescod met with victims' family members, who had many questions, but were asked by officials not to speak to the media until the news conference Thursday, she said.

She said some relatives of the victims screamed and shouted on the phone when she told them the news.

Aerial footage on Wednesday showed police searching cars in the garage of the suspect's home in south Los Angeles -- not far from the corridor where the victims' bodies were dumped.

Prescod said much of her organization's efforts focused on the area near Franklin's home.

"We went around there, going door-to-door to make sure people knew about the murders. At the time that we did that, most of the people hadn't even heard about the murders and people were concerned because they felt -- this is happening and we frankly don't know anything about it."

The LAPD confirmed that they are also searching a second home in the area listed under Franklin's name.

A 911 call made in 1987, reporting one of the murders, led police to a van they believed was involved. But the trail went cold.

In recent years, officials struggled to find new leads partially because the changing makeup of the neighborhood where the crimes were committed made it difficult to find witnesses, police said.

In May, new composite sketches of a suspect went up on billboards across Los Angeles as police intensified their hunt for the serial killer.