London - A father punched his five-month-old son to death as the two waited on a railway platform and then tried to shift the blame by telling police that a group of youths had carried out the attack, detectives said yesterday. Trevor McDonald (25) yesterday pleaded guilty to manslaughter at Newcastle Crown Court, where he was due to stand trial for the murder of his son Connor. The prosecution accepted the reduced charge and McDonald was remanded in custody to be sentenced on March 9th.