Further analysis of the phone showed it had been recording over several days of the trial, Greater Manchester Police said.
Det Ch Insp Andy Naismith said Mohamed’s actions were “unacceptable”.
He said: “This has been an extremely difficult trial for the family of Badri Issa, made more challenging through the conduct of certain individuals.
“I hope [the sentence] demonstrates how seriously we take the conduct of defendants’ families inside and outside of the courtroom.”
Mr Issa, 22, died after he was stabbed on Moss Side Lane East on 25 October.
Raami Mohamed, 21, of Fairy Lane, Salford, has been found guilty of murder and Kevell Blake, 20, of Bronshill Drive has been found guilty of manslaughter.
The pair will be sentenced at Manchester Crown Court on 7 June.
