Twenty-two-year-old Andrea Anaya lives alone with her four children, and with at least two serial killers on the prowl in the Phoenix area, she's worried.

"I can't sleep at night," Anaya said as she held her 3-month-old baby boy at a community meeting Wednesday night. "I am terrified. I'm terrified for the safety of my children, myself and my family."

Since last August, a man who has been called the "The Baseline Rapist" by local media and "The Baseline Killer" by Phoenix police is believed to have committed or be connected to eight robberies, seven sexual assaults and six murders.

Click here to visit FOXNews.com's Crime Center.

Police will not disclose what specific evidence leads them to believe the crimes are connected, but say time of day, location and suspect description all play a part.

On Wednesday, police added the September 2005 shooting death of 19-year-old Georgia Thompson in the parking lot of her Tempe apartment to the list of incidents connected to the Baseline Killer. Tempe police said James Mullins, 33, admitted to the killing while in a Kentucky jail on robbery charges.

Mullins was extradited and is being held in a Phoenix jail. Police said Mullins is definitely not the person known as the Baseline Killer. They said the killing is "definitively linked" to the Baseline crimes through forensic evidence, but would not elaborate.

Mullins met Thompson at the Scottsdale strip club where she worked the night of her killing, said Sgt. Dan Masters, a spokesman with Tempe police.

Masters said Tempe detectives are looking into whether someone was with Mullins at the time of Thompson's killing. Thompson was not sexually assaulted and detectives have not yet determined a motive for her shooting, Masters said.

A second series of possibly related crimes includes 34 incidents since May of last year in which 22 people were shot; five of them died from their wounds. That one or more killers also has targeted animals, killing four dogs and three horses.

Just four of those incidents have been definitively linked by evidence, police said, but the others are believed to be related because of how the one or more killers targets victims. People have been shot from behind while biking and walking and appear to be targeted at random, said Sgt. Andy Hill, a spokesman for the Phoenix Police Department.

The only thing the two possible killers have in common, Hill said, is the seeming randomness of the victims — a fact troubling members of the public who live in the central Phoenix area where many of the crimes have occurred.

"You look over your back when you're out," said Kelly Battese, 22, who lives in the area where many of the victims have been killed.

Sixty-year-old Diane Brown lives and works in the area as a teacher.

"I am very concerned," Brown said. "I'm not going out at night. There are some crazy guys out there."

Police Chief Jack Harris and Mayor Phil Gordon tried to calm Brown and other residents at the community meeting.

"We will not rest until we do track these people down," Harris said.

"We'll give every resource and continue to give every resource not only to catch these animals, these monsters, but others that continue to try to hurt you and I and our families," Gordon said. "We will get them."