Madison police said a 13-year-old boy was arrested on an attempted homicide charge after stabbing his older brother in the chest Saturday night.
Police said the brothers began arguing and the altercation became physical.
Police said the boy retrieved a knife and stabbed his 21-year-old brother in the chest in the 1700 block of Fordem Avenue.
Police said on Monday that the suspect gave a full confession and is being held in a juvenile detention facility.
The Dane County District Attorney's Office told WISC-TV the teen will be charged as adult. Prosecutors said the boy will be charged with attempted first-degree intentional homicide.
A court date has not been set, but an initial appearance could happen on Tuesday.
The victim was transported to a local hospital with a life-threatening injury and underwent surgery over the weekend. Police said the victim is in the Intensive Care Unit and is expected to live.