A man was given three years in prison for stabbing his brother for disrespecting their mother.The man, Joseph Michael Perrigan, 21, entered a guilty plea before Circuit Court Judge Bart Stanley to the charge of aggravated assault. He was given a three-year sentence on the felony count to be served in the state penitentiary.His sentence comes after he stabbed his brother following a confrontation at a residence on Kirby Street. According to police, Perrigan stabbed his brother under the left rib cage with a large knife.