This is part of a regular series that profiles America's most wanted criminals.

Murder suspects Hazel Head and Sherry Denise Halligan couldn't be any different. One was a hard-drinking, hard-living drifter who took advantage of lonely men she found in wanted ads. The other appeared to be a fragile victim forced into a crime of passion. But police say they shared a common bond: both women allegedly shot their lovers and left them to die.

Hazel Head

In 1998, Hazel Head parked Charles Barker's 1994 Lincoln Continental near Shreveport Regional Airport in Shreveport, La. after, police say, she left Barker slumped over in his trailer with a fatal gunshot to the head.

Investigators say Barker was just one of many in a long line of men Head hustled for money. She was already wanted in Nebraska for burning down a boyfriend's trailer seven years earlier.

Head typically targeted older men, usually truck drivers she met while hitchhiking across the country or working odd jobs like waitressing.

"Money was the reason she befriended older men," said Lt. Ed Baswell, a spokesman for the Bossier, La., Sheriff's Office. "She basically moved in and made herself at home and they welcomed her, not realizing she had a dark side."

Police say Head met Barker in Benton, La., after she placed a personal ad in the newspaper. They say only one thing attracted her to Barker: money.

"She was able to get to him, eventually moved in with him," Baswell said. "She took up with him and he took care of her."

Police say she paid him back by murdering him. Barker's pistol was found on a dresser in his master bedroom. Baswell said the bullet found in his brain matched the bullets found in his pistol. An undetermined amount of money was also stolen from his safe.

Click here for Head's Most Wanted poster.

Head was born in Dayton, Ohio, on Dec. 19, 1949, but grew up in Tennessee. Police say she had a troubled relationship with her mother, and at an early age liked to take on fake identities.

"Even as a kid, she would try to spice up her life by using different names," said FBI agent Steve Hayes. "She always pretended to be different people."

After she left home, she would call her mother to check in with her, and she would blame her for her problems.

Police can't say if she has had contact with her mom since Barker's 1998 murder. But they do say that Head, who was using the name Deianna Ray, fled the scene and vanished.

"She just seems to be able to disappear into thin air," said Baswell. "She's virtually untraceable."

Head may be traveling under other names, including Hazel Morgan, Willow Shield, Willow Spurbeck, Deianna Ray, Hazel Fatuch, Trease Tess Venable and Treasa Coyle.

She is wanted for first-degree murder and arson and unlawful flight to avoid prosecution. The FBI is offering a $5,000 reward for information leading to her arrest.

Sherry Denise Halligan

In January 2003, Sherry Halligan showed up at the LaGrange, Ill., Police Department and told police she had been driving back and forth on Highway 55 near Chicago for hours after shooting her ex-boyfriend five times and leaving him to die.

"She wasn't crying, she just appeared matter-of-fact," said Sgt. Renee Strasser of the LaGrange police department.

Halligan and Dennis Campbell, 50, dated in 2000, but the couple drifted apart when Campbell moved to Florida and met a new woman. When Halligan confronted Campbell in her LaGrange home about his new love, things quickly turned sour.

Halligan told police she had an argument with Campbell, and that there was a struggle. She said she feared for her safety, and so she shot him, Strasser said.

Strasser described Halligan as "cold and emotionless" when she came to the police station, yet she didn't fit the description of a cold-blooded killer.

"She's an attractive younger woman who did an unspeakable crime," said FBI agent Sean Burke. "If you looked at her photo, you wouldn't suspect her to be someone to murder."

Halligan told officials she wasn't sure if Campbell was alive or dead. Police sent a team to her house and found her ex-boyfriend's body on her back porch.

Halligan was arrested and charged with first-degree murder, but she didn't stick around to face justice. Released on bail, she attended some of her hearings, but she soon stopped showing up for court and has eluded authorities since.

Sometimes alleged criminals confess to a crime, and once "they get a little taste of what they are facing," they take off, Burke said.

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Click here for Halligan's Most Wanted poster.

Police say evidence shows Halligan had a history of working for escort businesses. They believe she might have returned to that line of work, since she could use a different name and a disguise to hide from her past, Burke said.

Halligan may be traveling under the aliases Denise S. Halligan, Denise Halligan, Sherry D. Halligan and Sherry Denise Halligan.

She is 5-foot-3, 108 pounds, with blond hair and green eyes. She was born in Illinois on December 1, 1958, and is wanted for murder and unlawful flight to avoid prosecution.

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