A 31-year-old woman turned herself in to Saint John police on Monday in connection with an aggravated assault on Friday.
Officers were called to a parking lot on Peters Street around 3 p.m. after someone was allegedly stabbed.
A 40-year-old woman was taken to hospital where police say she remains in serious condition.
The Major Crime Unit and Forensic Services were called in along with Justice and Public Safety canine services who helped with a search of the area.
Police say the accused was released from custody with a court date in February.
Anyone with information is asked to contact the Saint John Police Force at 506-648-3333 or Crime Stoppers at 1-800-222-8477.