Matvei Rumiantsev received a four-year prison sentence following an assault on a woman in London that was witnessed by Barron Trump.The son of the US President alerted emergency services from Florida after seeing the defendant attack the victim during a FaceTime call.Rumiantsev was convicted of assault occasioning actual bodily harm and attempting to pervert the course of justice during the legal proceedings.Although the jury acquitted him of more serious charges like rape, the judge noted that the convict could still face potential deportation.