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On New Year's Day, 2007, a homeless man rummaging for bottles and cans in a dumpster off Western Avenue in South Los Angeles - the notoriously neglected home of many of the megalopolis's poorest blacks and Latinos - made a grisly discovery.
Lying amid the trash, near a Christmas tree, was a black plastic rubbish bag. It covered a young black woman, naked but for a gold pendant. She had been shot in the back.
Police identified her as Janecia Peters, 25. The murder of a young black woman aroused little reaction, beyond family grief, as violent death in South LA is common and often unsolved. Indeed, Peters' murder was first misreported as a stabbing.
But this death was different. Late last month the Los Angeles Police Department stunned the megalopolis by revealing that Peters was the latest victim of the most prolific serial killer in California's bloody history.
The killer, dubbed the Grim Sleeper, has committed at least 11 murders since 1985; 10 black women raped and shot and one black man shot.
Disturbingly, he appears to have halted his grisly spree in 1988, after eight murders, only to re-emerge in 2002, then to disappear between 2003 and 2007.
In May 2007, following DNA analysis - the killer left traces of DNA on his victims' breasts - detectives finally concluded a serial killer was stalking their city.
"The day those tests came in, we realised we had a serial killer on our hands who has been active for 23 years," said LAPD Detective Dennis Kilcoyne, who heads the team of seven full-time investigators. Formed last May, the unit operated covertly until recently.
They have their work cut out. Their quarry may have killed others in what is at least a 23-year murder spree. Thirty-three cold cases - unsolved homicides - on LAPD files show similarities to the Grim Sleeper's known victims.
The news that a killer was in their midst provoked anger in South LA where residents asked why they were not warned earlier. "Leaving us out of the loop about something so important boggles the mind," said Bernard Parks, a former LAPD chief, who now represents South LA on the council.
Police say they had to walk a tightrope. Publicity would warn the public and might solicit tips but it could also alert the killer. However 18 months after the LAPD formed its task force, police seem no closer to catching the killer.
The biggest problem, says LAPD Chief of Detectives Charlie Beck, is the victims "all had some connection to high-risk street activity" - prostitution, drugs, or both - and warnings didn't "prohibit them from their activities".
The world's oldest profession is also one of the deadliest in LA where street prostitution is illegal. Beck rejects complaints police might have acted swifter had the murders occurred in a wealthy, white area. "That's nonsensical. There aren't any street prostitutes in Bel Air."
Besides assembling a team, the city has offered a $50,000 reward per victim and up to $500,000 for all the known cases - the largest reward ever offered by the city.
Porter Alexander, whose daughter Alicia was found dead in 1988 after she went to a local store, spoke at a press conference this month when the city posted its reward. "We hope they bring this menace to a halt," he said. "I know someone out there knows something or has seen something."
Little is known publicly about the suspect. The only witness, an unidentified black woman who survived a 1988 attack, says a black man in his mid-30s with short hair picked her up in an orange Ford Pinto, then raped and shot her in the chest. Amazingly, she persuaded him to let her jump from his car. This is the last known attack before 2002.
"Everything dried up," said Kilcoyne. "Detectives ran out of clues. They got on to other things."
At the time the Grim Sleeper murders were viewed as isolated crimes. But retrospective analysis shows striking similarities in his modus operandi. Besides selecting blacks, the killer shot his victims in the chest with the same .25 handgun.
Moreover, the female victims had all been found on or near Western Avenue, a long north-south boulevard through South LA. As for the only male victim - Thomas Steele, 36, found shot dead in the middle of an intersection - Beck says he "may have had some involvement with the prostitution business".
Based on the 1988 attack Beck says "we're looking for a male black, probably in his mid-50s". He cautions that this profile is vague as the witness was, and is, traumatised.
In 2001 Parks, then LAPD chief, instructed detectives to re-examine cold case murder books - over 9000 unsolved homicides dating back to 1960 - using new DNA technologies.
Four years later LAPD Detective Cliff Shephard found a match between Valerie McCorvey, 35, killed in 2003, and Princess Berthomieux, 14, killed in 2002 - both strangled and dumped near Western - and a preserved DNA sample taken from Lowe, killed in 1987.
When Peters was killed, and DNA linked her to the other murders, the LAPD quietly formed its task force. As is usual when hunting serial killers police also consulted profilers.
This may be of little value because, says Beck, the Grim Sleeper "may be outside the parameters of a 'typical' serial killer". Instead, the killer is likely to be a "regular customer who occasionally kills prostitutes. But not all prostitutes".
The biggest mystery, other than the killer's identity, is why he apparently stopped killing between 1988 and 2001, and between 2003 and 2007, although his bloody footprint may be linked to other cold cases from this period.
Detectives theorise he may have been abroad or out of the state. He may have been in prison but not had his DNA taken.
Currently, hopes are focusing on a "familial search" comparing the killer's DNA with a state database that may include relatives. If his familial DNA emerges in a search of over 1 million DNA profiles, police might be able to identify the Grim Sleeper.
It can't be done soon enough for people in South LA. The Grim Sleeper has been quiet for 20 months. The race for a familial DNA match is made urgent by the fear that the killer is biding his time waiting to strike again.
KNOWN VICTIMS
These are the victims and the dates they disappeared or were found.
* Debra Jackson, 29 - August 10, 1985.
* Henrietta Wright, 35 - August 12, 1986.
* Thomas Steele, 36 - August 14, 1986.
* Barbara Ware, 23 - January 10, 1987.
* Bernita Sparks, 25 - April 15, 1987.
* Mary Lowe, 26 - November 1, 1987.
* Lachrica Jefferson, 22 - January 30, 1988.
* Alicia " Monique" Alexander, 18 - September 11, 1988.
* Princess Berthomieux, 14 - March 19, 2002.
* Valerie McCorvey, 35 - July 11, 2003.
* Janecia Peters, 25 - January 1, 2007.
Source: LAPD