The man, 46, from Dandenong, who cannot be named, had been stalking his former partner for two months before he sent her a text message in June that read: "Anyway, Evang G and friends say hi to the jury girl ... They will come to visit for a private party ..."

"Evang G" was Evangelos Goussis, who had been standing trial with his co-accused Warren Shea and Mark Perry charged with murdering Chartres-Abbott.

A police investigation later revealed there was no link between the man and Goussis, who is serving a life sentence with a 30-year non-parole period for the gangland killings of Lewis Moran and Lewis Caine in 2004.

Chartres-Abbott had been on trial in the County Court in 2003 for the rape and mutilation of Mr Perry's ex-girlfriend at a hotel in Prahran in July 2002, when he was shot dead.

The jury forewoman was discharged on June 19 after informing the trial judge of the threatening text message.

Goussis, Mr Shea and Mr Perry were later found not guilty of murdering Chartres-Abbott.

Magistrate Donna Bakos on Thursday said that the man's conduct in sending the threatening text message had terrified the jury forewoman and threatened the administration of justice in Victoria.

Ms Bakos said the jury forewoman had been "distressed and incredibly fearful", believing the text message was a real threat to her and her family.

The forewoman had had to ask her former husband to move back in with her and her three children to make her feel safe from her ex-partner.

Ms Bakos said the man had not intended to interfere with the administration of justice but to instil fear in his victim.

The man had wanted the jury forewoman to believe Goussis and his associates were planning to pay her a visit.

Ms Bakos said the threatening text message had had a serious impact on the murder trial, with Justice Lex Lasry saying at the time: "I am extremely angry about this. This woman has committed a substantial period of time to this case as the foreperson and as a result of this man's reckless, cowardly conduct she now has to be removed from the jury."

Ms Bakos said it was fortunate the integrity of the murder trial had been preserved as 13 jurors had been empanelled, meaning the trial was able to go ahead with 12 jurors.

The magistrate said the man claimed to have been devastated by the end of his relationship with the jury forewoman in December 2013 but now accepted it was over and his actions had been "irrational, stupid and childish".

The man, who pleaded guilty to charges of stalking and failing to comply with a community corrections order after repeatedly breaching a family violence intervention order, was sentenced to six months' jail and an 18-month community corrections order.

The man, who appeared in the Melbourne Magistrates Court on Thursday on crutches after having been viciously attacked by two prisoners at the Melbourne Assessment Prison on July 28, has already served 163 days in pre-sentence detention.