A "sadistic" young woman has been caged for life for a homophobic killing after she kicked a father to death before laughing at her lifeless victim.Dionne Timms-Williams, who was 16-years-old when she punched and kicked Dr Gary Jenkins, was seen cackling by a witness during the horrific attack in July last year.Dr Jenkins, a 54-year-old, dad-of-two, was assaulted in the shadow of a historic castle and was seen and heard on audio CCTV begging for help as he was beaten to death.This week a court heard Dr Jenkins entered the grounds in the early hours of the morning before being attacked by Timms-Williams and two others within Bute Park, Cardiff.Timms-Williams could be heard shouting “do it” in a 15-minute recording, while she called the helpless victim a “f***ing pig”.She was later seen smirking in her custody picture and showed no remorse for the sickening assault, according to Mirror Online.Timms-Williams, now 17, Jason Edwards, 25, and Lee Strickland, 36, were jailed for a minimum of 84 years last week for the brutal robbery and killing.Judge Daniel Williams said the attack was motivated by “sheer homophobia”.Former neighbours of Timms-Williams have expressed their shock that such a “quiet girl” could commit such a heinous attack.They said that the teenager was previously a "daddy's girl" who had gone "off the rails" after her parents divorced.One neighbour told The Sun: “Everyone around here is absolutely stunned by this awful murder.“Dionne comes from two lovely parents, yet she’s gone out and done this.”Timms-Williams is said to have been “distraught” when her parents split up, although this does not explain the callous killing.Another neighbour added: “Believe it or not, Dionne was a lovely girl.