Man: No regrets about killing 39 women

• Police: A man arrested on suspicion of a killing confesses to dozens more


• Sailson Jose das Gracas tells a TV station that he's been killing for a decade


• "When I didn't kill, I would get nervous," he says


• Rio de Janeiro police say they have set up special teams to investigate the claims

(CNN) -- A Brazilian man has confessed to killing 39 women in the Rio de Janeiro region, police said Thursday -- shocking claims that, if confirmed, would make him one of the most prolific serial killers in the country's history.

In an interview with Brazilian broadcaster TV Globo, the alleged killer, Sailson Jose das Gracas, said that he carried out the first slaying when he was 17 and continued to kill over the next decade.

"I started robbing purses and small things like that," he told TV Globo. "And as I got older, I started having a different thoughts. My thoughts started changing. From stealing, I started thinking about killing."

Sailson, reported to be 26-years-old, said he didn't kill impulsively but stalked his victims.

Law enforcement officers meet in San Francisco in 1969 to compare notes on the Zodiac Killer, who is believed to have killed five people in 1968 and 1969. The killer gained notoriety by writing several letters to police boasting of the slayings. He claimed to have killed as many as 37 people and has never been caught.

Authorities said DNA recovered from the body of Mary Sullivan matches that of her suspected killer -- the confessed Boston Strangler, Albert DeSalvo. After a sample was secretly collected from a relative, DeSalvo's body was exhumed in July 2013 for more DNA testing. From mid-1962 to early 1964, the Boston Strangler killed at least 13 women. DeSalvo was stabbed to death in 1973 while serving a prison sentence for rape.

Ed Gein killed at least two women and dug up the corpses of several others from a cemetery in Wisconsin, using their skin and body parts to make clothing and household objects in the 1950s.

In 1973, Juan Corona, a California farm laborer, was sentenced to 25 consecutive life sentences for the murder of 25 people found hacked to death in shallow graves.

Joseph Paul Franklin was convicted in 1997 of murdering Gerald Gordon outside a St. Louis synagogue in 1977. Franklin was also convicted of at least five other murders, receiving a string of life sentences, but he suggested that he was responsible for 22 murders. He was best known for shooting Hustler publisher Larry Flynt, who was paralyzed from the attack. Franklin was executed in November.

In 1977, David Berkowitz, also known as Son of Sam, confessed to the murders of six people in New York City. Berkowitz, now serving six consecutive 25-to-life sentences, claimed a demon spoke to him through a neighbor's dog.

Cousins Kenneth Bianchi, seen here, and Angelo Buono were charged with the murders of nine women between 1977 and 1978. Also known as the Hillside Stranglers, the cousins sexually assaulted and sometimes tortured their victims, leaving their bodies on roadsides in the hills of southern California.

Wayne Williams killed at least two men between 1979 and 1981, and police believed he might have been responsible for more than 20 other deaths in the Atlanta area. Williams was convicted and sentenced to two life terms in 1982.

After serving 15 years for murdering his mother, Henry Lee Lucas was convicted in 1985 for nine more murders. Lucas was the only inmate ever spared from execution by then-Texas Gov. George W. Bush.

Richard Ramirez, also known as the Night Stalker, was convicted of 13 murders and sentenced to death in California in 1989. The self-proclaimed devil worshipper found his victims in quiet neighborhoods and entered their homes through unlocked windows and doors.

During a routine traffic stop, a policeman found a dead U.S. Marine in the front seat of a car driven by Randy Steven Kraft. Kraft was linked to 45 murders and sentenced to death in 1989. He would pick up hitchhikers, give them drugs and alcohol, sexually assault them and then mutilate and strangle them.

Ted Bundy raped and killed at least 16 young women in the early to mid-1970s before he was executed in 1989. A crowd of several hundred gathered outside the prison where he was executed, and they cheered at the news of his death.

Jeffery Dahmer was sentenced to 15 consecutive life terms for the murders of 17 men and boys in the Milwaukee area between 1978 and 1991. Dahmer had sex with the corpses of his victims and kept the body parts of others, some of which he ate. Dahmer and another prison inmate were beaten to death during a work detail in November 1994.

John Wayne Gacy killed 33 men and boys between 1972 and 1978. Many of his victims, mostly drifters or runaways, were buried in a crawl space beneath his suburban Chicago home.

Joel David Rifkin was stopped by police for driving without a license plate when a body was found in his pickup truck. Rifkin killed 17 women in New York City between 1991 and 1993 and was sentenced to life in prison.

Charles Ng, seen here, and accomplice Leonard Lake tortured, killed and buried 11 people in northern California between 1984 and 1985. After the men were arrested for shoplifting, police found bullets and a silencer in their car and took them into the police station for questioning. Lake killed himself there with a cyanide pill. Ng was later sentenced to death.

Robert Lee Yates Jr. killed 15 people, most of them between 1996 and 1998. He buried one of them in a flower bed by his house in the Spokane, Washington, area. Most of his victims were prostitutes or drug addicts he killed in his van. He is on Washington's death row.

Gary Leon Ridgway, also known as the Green River Killer, confessed to 48 killings after his DNA was linked to a few of his victims. Remains of his victims, mostly runaways and prostitutes, turned up in ravines, rivers, airports and freeways in the Pacific Northwest.

Aileen Wuornos was executed in Florida in 2002 for the murders of seven men whom she had lured by posing as a prostitute or a distressed traveler.

Derrick Todd Lee was accused of raping and killing six women in Baton Rouge, Louisiana, between 2001 and 2003. He was arrested in Atlanta for the murder of Charlotte Murray Pace, convicted in 2004 and sentenced to death.

Danny Rolling pleaded guilty to the 1990 murders of five students he raped, tortured and mutilated in Gainesville, Florida. Rolling was also responsible for a separate 1991 triple homicide in Shreveport, Louisiana, and he was executed in 2006.

Angel Maturino Resendez, also known as the Railway Killer, was a drifter from Mexico. During the 1990s, he would rob and kill his victims near railroad tracks on both sides of the border, then hop rail cars to escape. Resendez was executed in 2006.

Pig farmer Robert Pickton was charged with 26 counts of murder after police found the bodies of young women on his farm in Port Coquitman, British Columbia, Canada. He was convicted of six murders in 2007, and he is serving a life sentence.

The BTK Strangler, Dennis Rader, killed 10 people between 1977 and 1991 in the Wichita, Kansas, area. He was convicted to 10 consecutive life terms in 2005. Rader named himself BTK, short for "bind, torture, kill."

Police found the decomposing and buried bodies of 10 women, and the skull of another woman, at the Cleveland home of ex-Marine Anthony Sowell. Sowell was convicted and given the death penalty in 2011.

Chester Dewayne Turner was charged with murdering 10 women and one unborn fetus in the Los Angeles area between 1987 and 1998. In 2007, Turner was sentenced to death for the murders and charged with four more murders in 2011.

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Photos: Infamous serial killers

Rio police said they arrested Sailson on Wednesday on suspicion of killing a woman in the suburb of Nova Iguacu. He confessed to that homicide and then told police about the other killings, they said.

Sailson described his need to kill as pathological.

"When I didn't kill, I would get nervous," he told TV Globo. "I would pace around the house, and then when I killed, it calmed me."

Police chief Marcelo Machado told TV Globo that Sailson is also suspected of killing a 2-year-old boy, the son of one of the dead women.

Fast Facts on serial killers

'No regrets'

Specialized police teams are carrying out an investigation into his claims.

"We must carefully examine, one by one," Machado said.

Police said they had located four other cases from the homicide division that had the same modus operandi presented by Sailson, who told them he used knives to kill.

Police said they had also arrested a man and woman, who Sailson said had told him to kill the latest victim.

The self-declared killer said he had "no regrets" about his actions and would kill again if set free.

"What is done is done," he told the TV network. "If I leave here in 10, 15, 20 years, I'll go back to doing the same thing."

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