Joshua Molnar, 18, who fatally stabbed Manchester Grammar student Yousef Makki with an illegal flick-knife in March, was cleared of murder and manslaughter, but handed a 16-month detention order for possessing an offensive weapon and perverting the course of justice by lying to police.
The court ruled Molnar had acted in self defence in what has been described as a contentious ruling.
His parents hired crisis management firm MC2 Communications to handle media relations in the wake of the controversial ruling, which included an interview with the Sunday Times.
The move angered Makki’s family, with mother Debbie telling the telling the media: "Who do the Molnars think they are having a publicist? They’re hardly Posh and Becks. They are shameless. They have shown no remorse to us during or since the trial.
"We’ve never heard anything from them. Surely, as human beings they should sympathise with us losing such a huge part of our lives. Instead, they seem to be more worried about tainting their reputations."
MC2 released a statement defending its appointment, pointing out that: "Our role is to help articulate clear communications and to manage the sheer logistical challenge of national and international media demands.
"As one of the largest independent agencies in the North and one of the leading crisis management consultancies, MC2 is often at the centre of some of the most emotive and sensitive issues affecting both businesses and individuals."
The case raises questions about where PR agencies should draw the line in choosing to represent clients in contentious and sensitive circumstances.