By James Eng, NBC News
In law enforcement, as in most every other profession, there are good ones and bad ones, but what most people seem to remember are the really bad ones.
Manuel Pardo, a former Florida police officer turned serial killer who was scheduled to be executed Tuesday, was one of the latter, officials say. He shot nine people to death in the late 1980s, claiming he was a "soldier" ridding the streets of the wicked.
Most of Pardo's victims were reportedly involved with drugs, and Pardo claimed he was doing society a favor by ridding the streets of low-lifes who "have no right to live." Authorities say he was a cold-blooded serial killer; one retired detective described him as "Ted Bundy-esque," while a retired prosecutor called him "very cold."
Michael Tabman, a former Fairfax County, Va., police officer and former FBI agent, said law enforcement agencies have better screening tools these days to weed out potential problem applicants, "but we haven't perfected predicting behavior."
He said people attracted to police work often have personalities that are "machismo-oriented" and "comfortable with a lot of authority," among other traits.
"A lot of that is a type of personality that in a perfect storm … can morph into anti-social behavior," said Tabman, an author who also blogs about crime and security.
Herewith are some other notorious cases involving cops gone bad:
M. Spencer Green / AP file
Former Bolingbrook, Ill., police Sgt. Drew Peterson arrives at the Will County Courthouse in Joliet, Ill., for his arraignment on charges of first-degree murder on May 8, 2009.
Before his 2009 arrest, according to media reports, Peterson seemed to taunt authorities, joking on talk shows and even suggesting a "Win a Date With Drew" contest.
After his conviction, Savio's family members said justice was finally served. "Game over, Drew," Stacy Peterson's sister, Cassandra Cales, said. "He can wipe the smirk off his face. It's time to pay."
Via KTLA / AP file
A frame from a video shot by George Holliday from his apartment in a suburb of Los Angeles shows a group of police officers beating Rodney King as other officers watch on March 31, 1991.
Rodney King beating
A year later, a California jury acquitted three officers and deadlocked on charges for a fourth. The verdict sparked violent race riots in Los Angeles, and by the time order was restored, more than 50 people had died.
A federal jury later convicted two of the police officers, Stacey Koon and Laurence Powell, of a federal charge of violating King's civil rights and sentenced them to 30 months in prison.
King died in June at age 47.
Katrina bridge shootings
Getty Images file
Cars pass over the Danziger Bridge July 14, 2010 in New Orleans.
In August 2011, four former New Orleans police officers -- Kenneth Bowen, Robert Gisevius, Anthony Villavaso and Robert Faulcon – were convicted of civil-rights violations and firearms and other charges in the shootings. A fifth former officer, Arthur "Archie" Kaufman, who was assigned to investigate the shootings, was convicted of helping to orchestrate a cover-up.
"The officers who shot innocent people on the bridge and then went to great lengths to cover up their own crimes have finally been held accountable for their actions," Thomas E. Perez, assistant attorney general for the Justice Department's civil rights division, said when the men were sentenced to long prison terms in April.
Former New York City police officer Justin Volpe in 1997.
Abner Louima beating
One cop, Justin Volpe, was sentenced in 1999 to 30 years in prison for what the judge called an "unusually heinous" crime and a "barbarous misuse of power." Another, Charles Schwartz, who was initially accused of holding Louima down, pleaded guilty to perjury and was given a five-year sentence. Two other officers who were indicted for allegedly trying to cover up the assault had their convictions reversed due to insufficient evidence.
Chicago Sun-Times / AP
Former Chicago police officer Jon Burge, convicted of lying about the torture of suspects, walks to his attorneys' office following the first day of his sentencing hearing at the federal building in Chicago on Jan. 20, 2011.
Louima sued New York City and its main police union and won a $8.75 million settlement.
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Although Burge was protected by the statute of limitations on the claims of abuse, he was convicted of lying about the torture. He was sentenced in January 2011 to 4 ½ years in prison.
The city agreed to pay more than $7 million to settle two torture lawsuits involving Burge.
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