WILKES-BARRE – A city teen charged with violently shaking his then-3-month-old son pleaded no contest to related charges Tuesday. Kashawn Butler, 18, of Old River Road, entered the plea before Judge Fred Pierantoni to charges of aggravated assault, simple assault, endangering the welfare of children and reckless endangerment of another person. City police and the Luzerne County Detective Bureau allege Butler shook the baby, Sincere Butler, when the infant spat up after a feeding inside his residence on Dec. 4. Assistant District Attorney James McMonagle said prosecutors are seeking a mandatory minimum of five years in prison when Butler is sentenced on Oct. 11. Butler faces a maximum of 20 years in prison on the aggravated assault charge. Butler’s attorney, Christopher O’Donnell, said his client was entering the no-contest plea, which does not necessarily mean he is guilty of the charges, only that he does not dispute the facts of the case. “He did not mean to injure the baby,” McMonagle said. Investigators say Butler fed his son when the mother, Mercedes Pearson, and her mother, Lashawanda Pearson, left the residence to walk to a store on Dec. 4. Butler told authorities he shook the infant after he became upset at the baby for throwing up and crying, according to the criminal complaint. Court papers say Butler initially denied he injured his son and said the baby stopped breathing after throwing up. City paramedics revived the baby and rushed him to Wilkes-Barre General Hospital. The baby was then flown to Geisinger Medical Center in Danville. Doctors at the Danville hospital said the baby had injuries consistent with shaken baby syndrome, including hemorrhages behind the eyes. Sincere Butler has since been released from Geisinger and is currently staying at St. Joseph’s in Scranton, an assisted living facility. Prosecutors have said the baby will require round-the-clock care for the rest of his life, is likely blind and will never fully recover from his injuries.