There were plenty of laughs as war stories were shared, such as the suburban detective who shot a beer bottle off the head of an uncooperative suspect William Tell style. It worked as the bloke had a change of heart (and underwear), soon seeing the advantages in telling the truth.

They were masters of the craft, when you only joined the squad by invitation, and between them dealt with hundreds of murders with a conviction rate well over 90 per cent.

But no one has a perfect record and it is the unsolved cases that grate with one retired investigator observing the frustration only gets worse with age.

Like the deepest mental bruise the questions remain: Did I miss anything? Did a liar suck me in? Is the name of the killer still in the file?

This is not about ego but obligation. A good homicide detective creates a bond with the victim's family and feels a duty to find the truth.

It is central to the squad's code: "No greater honour will ever be bestowed on an officer, or a more profound duty imposed on him, than when he is entrusted with the investigation of the death of a human being. It is his duty to find the facts, regardless of colour or creed, without prejudice, and to let no power on earth deter him from presenting these facts to the court without regard to personality."

Which is why retired homicide detectives welcome a call from today's cold case investigators because it means that one of their unsolveds is back on the front burner.

Not so long ago each homicide crew was given some unsolved cases and asked to have a nibble when time permitted, which it rarely did as new murders always took precedence.

But now embedded within homicide is a dedicated cold case unit headed by experienced Detective Senior Sergeant Peter Trichias with eight investigators. It is a massive investment in a labour intensive business when a case is deconstructed and then rebuilt.

Old witnesses have to be found, alibis re-examined and exhibits re-tested. Sometimes the dead ends remain impenetrable but sometimes there can be a breakthrough.

Cold cases have been cracked in recent years through DNA technology or when fresh witnesses come forward. And sometimes it just takes a knock on the door. In one case an alibi witness simply had a change of heart. In another a key figure came forward to free himself of guilt.

In the case of Michelle Buckingham, a 16-year-old murdered in Shepparton in October 1983, it was a series of stories in the local paper 29 years later that persuaded a local man, Norman Gribble, to come forward. It was a picture of Michelle's mother Elvira, on page one, which made him finally act.

He said his brother-in-law, Stephen Bradley, had confessed to the crime, adding he had bandaged Bradley's hand that had been injured during the murder. Gribble eventually gave evidence and in 2015 Bradley was convicted and sentenced to a minimum of 21 years.

Publicity can be a proven investigative weapon, which is why police have teamed up with Channel Seven in a new television series starting in a couple of weeks called Million Dollar Cold Case.

Each week the cold case crew open their files on murders and will offer a million-dollar reward for information that leads to an arrest and conviction.

"Someone out there will know who has done these murders and they will have key pieces of information," says the head of the homicide squad, Detective Inspector Mick Hughes.

"There is always someone who knows," adds Detective Sergeant Paul Rowe.

This is not a blanket bombing approach for police are looking for specific information on identified suspects. There are about 280 cold murder cases on Victoria's book from the 1950s but the 10 to be highlighted over four weeks have been selected because they are the ones closest to solution.

"We are trying to think laterally here. These are the cases we think are the most viable and solvable," says Hughes.

There is another reason police have been so specific. Publicity brings hope to grieving relatives that can be dashed if nothing progresses. It is simply cruel.

"We would love to look at all the cases but the reality is we can't," Trichias says. "In the majority of the cases to be examined here there is a specific line of inquiry and we have identified suspects. We went to put ourselves in the strongest position we can to progress these investigations."

These sort of TV shows can be done exceptionally badly with poor reconstructions and fake dialogue so it is with some relief we can report after viewing the first two episodes that it is evidentiary based, understated and very good.

With a seemingly unquenchable thirst for true crime this series should rate its head off although the police involved are more interested in leads than Logies. Indeed, in this case it was a police initiative and as Million Dollar Cold Case executive producer Debbie Byrne says, "We jumped at the chance."

And then there is the cash. The million-dollar reward system has already proven a winner. The man who helped finger drug boss Tony Mokbel was paid near that figure. A professional musician, he rang members of his band one day to say he wouldn't be making their next gig and that his phone would never answer again.

He has since disappeared, has a new identity and certainly no longer needs to play Herb Alpert montages on pub nights.

And former lawyer Andrew Fraser, the star witness in the prosecution of serial killer Peter Dupas over the 1997 murder of Mersina Halvagis, received an undisclosed (read huge) reward for his evidence.

The tragedy is the man behind the reward system, John Magill, will probably never see justice for his murdered daughter, Jane Thurgood-Dove.

She was shot dead in front of her children when she drove into her Niddrie driveway in November 1997. Police now know it was a mistaken identity killing where the real target was the wife of a gangster who lived in the same street.

Eventually two of the hit team were identified but both died before they could be interviewed, which has left the case stalled.

It was Magill who lobbied for the reward fund that is being used in Million Dollar Cold Case. The first episode highlights the 1984 murders of Margaret Tapp, a 35-year-old nurse and part-time law student, and her nine-year-old daughter Seana who was also viciously sexually assaulted in their Kelvin Drive, Ferntree Gully home.

The homicide crew were on their way home when they got the call. One was Brendan Murphy who recalls, "The images of both Margaret and Seana Tapp, those are the sort of images that never ever leave you."

The program interviews past and present investigators, relatives and witnesses and identifies suspects. You see the terrible burden that is carried by family members in unsolved murders. Tragically Tapp's son Justin never recovered from the double loss and died nearly 30 years later in London, almost certainly by his own hand.

In one case you see Christine Loader, the grief stricken mother of a teenage victim, Ricky Balcombe, killed in 1995, who was devastated when the charges against the suspect were dropped. But as they were withdrawn before trial he can be charged again and that is clearly the game plan.

We watch as Senior Detective Lisa Metcher tells her, "Let me do some of the hard work for you, because that's my job, that's what I do."

Christine tells the program, "Meeting Lisa today for some reason just like lifted a bit of weight off my shoulders. It was like having a friend there. She wasn't just a detective."

Traditionally homicide detectives have a strong working relationship with the media. Murders are big stories and the smart investigator learns to manage the flow of information. When a case is going smoothly detectives bunker down but when it is a struggle they will release selective information either to look for leads from the public or crank up the pressure on a suspect.

The master of the game was Paul Delianis who, when head of the Homicide Squad, knew how to create a headline when he wanted a new lead. At one time he would ring a mate on the news desk at the Sun newspaper to ask the strength of the story list. If it was big news day he would remain silent, if there was a hole on page one he would drop his story.

Million Dollar Cold Case is riveting television. It will rate and will probably be replicated in other states when it takes off. But will it catch the killers? That is the real million-dollar question.

Million Dollar Cold Case: Begins on Channel 7, March 15, 9pm.