The Law Society says anger being directed at the lawyer who defended Clayton Weatherston is misplaced.
Judith Ablett Kerr, QC, has reportedly received death threats, hate mail and her property has been damaged.
Weatherston was convicted in July of murdering his former girlfriend Sophie Elliott, after stabbing 216 times in January last year. He had admitted a charge of manslaughter, claiming that he was provoked into killing her.
Law Society president John Marshall, QC, issued a statement on Wednesday, strongly defending Mrs Ablett Kerr.
He said the criticism indicates people do not understand a lawyer's job.
Mr Marshall says the general rule is that lawyers must accept clients who seek their services. Their professional rules state that lawyers cannot, without good cause, refuse instructions from prospective clients.
Mr Marshall says lawyers must put forward any proper defence that their client wishes.
Another member of Weatherston's defence team, Greg King, says he is shocked by the attacks.
Mr King says defence lawyers expect some flak but is taken aback by the scale of the criticism. He says he is surprised it is coming from some church ministers and senior academics.