CHILLICOTHE (AP) — In the span of little over a year, six Chillicothe women have turned up missing or deceased, instilling fear in the citizens of the town of 21,000 that a possible serial killer could be at work.

All of the victims shared similar backgrounds. They were mothers in their 20s or 30s, some allegedly used drugs or worked as prostitutes and some knew each other.

Four of the women have turned up dead in area creeks and after the discovery of the fourth victim, Tiffany D. Sayre, 26, a law enforcement task force, including the FBI, was launched.

“I actually have two detectives assigned to their task force down there,” said Pickaway County Sheriff Robert Radcliff. “We’ve partnered with the 23 Pipeline Task Force. They’re definitely familiar to us and there are connections in the local area with us.”

A rally was held Monday in Chillicothe by local officials in law enforcement. During the rally, the reward for information on the missing women and the crimes was raised from $2,500 to $5,000 per victim.

Two women have not been found yet and are still determined missing.

Charlotte E. Trego, 28, was last seen in Chillicothe May 3, 2014. She is a white female, 5’ 4” and weighs 150 pounds. She has brown hair and blue eyes and was the first victim to vanish. Trego had dealt with addiction and had checked into a rehab facility.

Wanda J. Lemons, 38, was seen in Chillicothe last on Oct. 3, 2014. She is a white female, 5’ 6” and weighs 135 pounds. She has brown hair and blue eyes and is a mother of five and grandmother of two.

Four women have turned up dead in various areas around Chillicothe.

Tameka Lynch, 30, was reported missing in May 2014. She was found by a kayaker on a sandbar in Paint Creek three weeks after she went missing. Lynch was a married mother of three. She had been diagnosed with lupus and is reported to have had problems with drugs and prostitution.

The Ross County Coroner’s office ruled that Lynch died of a multiple drug overdose. However, Lynch’s mother stated she was scared of water and believed she was put there after her death.

Shasta Himelrick, 20, was reported missing Dec. 2014 and was pregnant with her first child. She had been visiting her grandmother when she received a text message and said she needed to leave and would be back.

A surveillance camera at a Chillicothe gas station recorded her entering the business and she was later found dead in the Scioto River. Her abandoned car had been located near a bridge south of Chillicothe with all of the doors open and the battery dead.

There were non-fatal levels of cocaine and oxycodone in her body and the Ross County Coroner’s Office ruled the death a suicide.

Timberly Claytor, 38, was found dead along Trego Creek Rd. in Massieville in May of this year.

Claytor, a mother of two, had been shot in the head three times. She was friends with three of the other missing women and was last seen getting into a car with a male at approximately 3:30 a.m.

Jason A. McCrary, 36, a convicted sex offender, has been determined as the prime suspect in Claytor’s case but has not yet been charged for the crime.

Tiffany D. Sayre, 26, had last been seen in Chillicothe in May of this year. She had been working with a friend at a motel and left to run to her grandmother’s house. She went missing at approximately midnight.

A couple discovered Sayre’s naked body wrapped in a bedsheet at a nature preserve south of Chillicothe.

“We’re trying to be proactive,” said Sheriff Radcliff. “The thing of it is, people should use caution. Don’t go to unfamiliar areas by themselves, use good common sense, don’t go out at night by yourself, don’t go to Chillicothe at night alone. We’re trying to stay in the loop. We want to know what’s going on and if we can help them in any way.”

Agencies are investigating all four deaths, including those that had previously been labeled a suicide.

Those who may have any information on the missing or deceased women are encouraged to contact the Task Force Hotline at 740-774- FIND (3463) or FindMe@RossSheriff.com.

Anyone with information that could lead to the arrest and conviction of a suspect should contact 740-773-TIPS (8477) or SouthernOhio CrimeStoppers.com.