Khalila Southall, 30, was arrested Sept. 3 in Rochester, Minn., where she had fled after allegedly killing Lakeisha Tate, 28, Aug. 26, police and prosecutors said.
Southall -- who is charged with first-degree murder -- allegedly confronted Tate as Tate was leaving a gas station convenience store where she had made a purchase, the Chicago Tribune reported.
Assistant State's Attorney Joe Crocker said in court Thursday the two were fighting in the doorway when Southall shot Tate in the leg and torso with a handgun before leaving the scene.
Tate was taken to a hospital, where she was pronounced dead Aug. 27.
Several people witnessed the killing and several shot video of it, prosecutors said. In addition, Southall left an ID card at the scene, the report said.
Prosecutors said evidence against Southall included a .25-caliber semiautomatic handgun found at her boyfriend's home, where investigators also found a dress matching the one seen in video of the slaying, the newspaper reported.
Prosecutors did disclose details of the Facebook feud.