Karen Brown allegedly shot and killed a man who attacked and robbed her near a hotel in Moorebank, in south-western Sydney, last Monday.
Yesterday police ordered Ms Brown to report for a formal interview but she failed to appear.
The 41-year-old spoke to the Seven Network and a newspaper over the weekend for a fee, despite telling police she was too unwell to speak to them.
Mr Cowdery says the media's involvement in such cases has the potential to interfere in the justice process.
"It is a very serious issue and something that we need to be addressing very carefully and we need to be assessing, I think very carefully, also the position of police in relation to the media when these kinds of issues arise," he said.
"There have been some very disturbing events over recent times that have put the spotlight on the conduct of police, the conduct of the media and their relationship with the criminal justice process."
The Seven Network has defended interviewing Ms Brown.
Seven's news director Peter Meakin has rejected claims that the interview interfered in the justice process.
"When we did the deal she had not been charged with anything. She was an innocent person in fact and by presumption," he said.
"If people genuinely believe the jury system is so fragile that someone seeing a television interview six months before a case comes to court is going to somehow prejudice their judgement, then it's time we ban the jury system."
By Starsky and Hutch 2 August 04
THE DOG: When 7 did the deal Karen was too sick to be charged she said? Ban Channel Seven!
