The most recent suspect, Thelma Carter, is accused of fatally striking her boyfriend with a stiletto-heel shoe.
Carter, 46, and Judy Washington, 52, are the first two female murder suspects of 2011 in Augusta.
So far this year, the Richmond County Sheriff's Office has investigated 14 homicides.
In 2010, two women were charged in the 38 homicides the sheriff's office investigated.
According to the U.S. Department of Justice, 9.6 percent of homicides from 1976 to 2005 involved women killing men. The largest percentage, 65.3 percent, involved men killing men.
Deputies were called shortly before 4 a.m. Sunday to a home on Ramsey Street, where they discovered that 45-year-old Steven Mikel had been shot at least twice.
He died from his injuries less than an hour later at Medical College of Georgia Hospital.
Washington, of the 1700 block of Essie McIntyre Boulevard, was identified by witnesses and charged with murder, possession of a firearm during the commission of a crime and possession of a firearm by a convicted felon.
Capt. Scott Peebles said Washington and Mikel were not romantically involved but had an ongoing argument.
"He may or may not have assaulted her in some way the day before, but at least they had an argument," Peebles said.
On Sunday evening, Robert Higdon, 58, was involved in an altercation with his live-in girlfriend in the trailer they shared at Augusta Mobile Home Estates, 2526 Milledgeville Road.
His girlfriend, Carter, was charged with murder after she struck Higdon in the head with the spike heel of a shoe, police said.
Authorities were called to the home Monday morning when Carter returned to the scene and notified authorities.
Investigators are unsure how many times Highdon was struck with the shoe before he died.
An autopsy is scheduled for this morning at the Augusta Crime Lab.