Tennessee and Alabama investigators are working together to try to identify a suspect in a series of killings that left six people dead in the two states.
Tennessee Bureau of Investigation spokeswoman Kristin Helm said Wednesday that investigators are following evidence from four crime scenes that they hope will lead to an arrest or allow them to issue an alert to the public for a suspect.
Helm said the investigation has found that one of those who died, Warren Vincent Crutcher, knew the other victims.
Three women and a toddler were killed at two homes in Fayetteville on Monday while a man, Jeffrey Pope, and Crutcher were found dead Tuesday in two separate locations in Madison County, Alabama.
Helm said Crutcher had former or current relationships with the three women and was an acquaintance of Pope.
The bodies of 22-year-old Chabreya Campbell, 21-year-old Amber McCaulley and Campbell's 18-month-old son Rico "Rashad" Ragland were the first discovered around Noon on Monday at Campbell's home on Huntsville Highway, about 100 miles south of Nashville.
Investigators said Campbell was six months pregnant. Her three-year-old son, Vincent Crutcher, was in the home at the time of the murders, but was unharmed.
The young boy reportedly used his mother's cell phone and made a call, saying his mother and brother wouldn't wake up.
McCaulley's aunt told Nashville's News 2 she leaves behind a two-month-old baby.
"My sister put in a missing report on her early this morning because she didn't come home last night and it's just not like her not to come home, she has a two-month-old baby that she loves," Regina Leslie said Monday.
Leslie said it is unclear how she and Campbell knew each other.
She added, "I know most of [McCaulley's] friends and I didn't know [Campbell]. Most of her friends, they're at my house on Sundays for dinner."
Within hours of the initial discovery, 21-year-old Jessica Brown was found dead in her Fox Wood Drive home, less than five miles from the first crime scene. Her two-month-old son was in the home, but was unharmed.
On Tuesday morning, Crutcher, 24, who authorities wanted to question about the murders, was also found dead.
"I would say he is a person of interest in the original case, continues to be so," Chief Deputy Chris Stephens of Madison County Sheriff's Office in Alabama said. "However, he is also now certainly a victim."
Stephens continued, "What we're attempting to do at this point is identify a common thread that may have brought all this together. We have no motive, no mechanism as to why all this may have occurred, but we're working to try to determine that."
It is not clear if the murders are the work of one person or several.
Autopsies will be performed on the six victims to determine causes of death.