Police say Paul Jacob Stiles, 28, has been arrested in the attack that happened shortly before four o'clock.
Stiles reportedly went to an apartment complex on Boston Avenue looking for a man named "Marvin" who lived in an upstairs unit.
After reportedly knocking on several apartment doors, he went downstairs and knocked on the front door of Kimberly Hunt, 43, telling her that he needed gas and to use the phone.
According to Misty McGhee, the mother of the injured girls, Stiles also offered to help with her vehicle that was stuck in the mud next to the apartment and told her to wait at the vehicle.
She told police after waiting about 30 minutes, Stiles came out of the apartment and appeared out of breath, commenting that he would have to help with her vehicle some other time. McGhee then went back to the apartment and found her two daughters, aged 12 and 15, and Hunt, had been stabbed. McGhee and a third child inside the apartment were not hurt in the incident.
Police say both girls were stabbed several times and the 15-year-old had to be flown to Arkansas Children's Hospital in Little Rock for treatment.
Police found Stiles at a house nearby and took him into custody. At first he was only charged with Possession of Methamphetamine and Possession of Drug Paraphernalia. He also had an outstanding warrant from Crawford County. After police interviewed Stiles, he was also charged with two counts of first degree battery and one count of second degree battery.
He is being held at the Sebastian County Detention Center without bond.
Anyone with information about this crime is asked to call the Fort Smith Police Department at (479)709-5000 or dial 78-CRIME.