It also marked the latest round in an increasingly frenetic media battle to cover a baffling crime. A hundred days after the television presenter was gunned down with a single shot to the head outside her house in west London, the police seem no nearer to catching the killer. But as time goes by, pressure on Scotland Yard to provide updates, exclusives, interviews and a decent breakthrough intensifies.
The victim, circumstances, and level of media interest are unprecedented. The moment the news broke that the widely admired presenter had been shot dead on her doorstep, on 26 April, the media news machine went into overdrive. Some newspapers even suggested that the reaction to Miss Dando's death was similar to the mourning that followed the fatal car crash of Diana, Princess of Wales.
The media relations got off to a bad start after Scotland Yard refused to reveal the cause of death until the post-mortem examination had been completed - forcing some papers to hold back their first editions. After an initial flurry of press conferences, the release of an E-fit of a "sweaty man" seen running away from the scene of the crime, and sometimes contradictory reports of sightings of a Range Rover, things started to go quiet.
Some far-fetched explanations - such as that the murder had been carried out by a Serbian hitman in revenge for Miss Dando's appeal to help refugees - were largely media-led. The statement of a detective that the police had not ruled out the possibility was seen as a licence by some news editors to suggest that it was a major line of inquiry.
The apparent lack of progress has resulted in journalists seeking their own explanations and exclusives. The hitman was linked to Mossad, the Israeli secret service (The Express); he was a former SAS man (News of the World); he fled to Belgium on a bus (The People).
In high-profile crime cases the media may take the "bad cop" line - criticise the police. The problem with this approach is that you risk alienating your number one source. In the Dando case the Yard were accused by, among others, The Mail on Sunday, of not holding enough press briefings, failing to interview likely suspects, not giving out enough background guidance and providing muddled information.
The Sunday newspapers, which need to come up with a weekly exclusive, led the charge, partly because they are less reliant than daily reporters on maintaining good relations with the police. The latest theory was touted on a front page last weekend by The People which "revealed" that a "Spurned Mafia Boss Killed Dando". Meanwhile, The Sunday Times suggested that police were probing a link with IRA or loyalist hitmen.
On the other hand, most crime journalists will try to balance the need for a lively news story with the need to preserve good police contacts - though, unfortunately, for the police, bad news is always far more interesting than good.
The BBC has a tricky job in reporting on one of its own. There was criticism, both inside the BBC and outside, of the coverage and prominence given to the story. "Senior management started doing the headless-chicken job and were desperate not to miss anything," said one insider. "People who would not usually worry about how accurate and informed a piece was, suddenly started taking a very close interest."
But the biggest intake of breath was reserved for the way the BBC dealt with an exclusive interview with Miss Dando's fiance, Dr Alan Farthing. The interview was set up for the 6pm News by Stephen Cape, the BBC's crime correspondent, but at the last moment it was decided that Anna Ford, a friend of Dr Farthing, should conduct the live interview. To the shock of some insiders Dr Farthing - who, as Dando's fiance, had been considered a suspect before Scotland Yard ruled him out of the hunt - was greeted on air with a kiss by Anna Ford. This was considered less than objective by some.
Detective Chief Inspector Hamish Campbell, one of the officers leading the inquiry, and the public face of the murder hunt, has became increasingly frustrated and annoyed at the criticism, and by what he believes are a series of fantasy stories that are harming the inquiry. In several cases the police have had to redeploy officers to investigate these stories, in case they have missed something.
Scotland Yard says it is also concerned that newspapers have been assigning "showbiz" reporters and star columnists to cover the case. "They have no idea about how a murder investigation works. Someone recently suggested that we hire a private detective to solve the case, which is ludicrous," said a police source. He added: "We have tried to be as frank as possible, and we have given guidance which papers have simply ignored.
"It's hard to satisfy the demands of everyone; you cannot keep back information just to satisfy different groups, such as the Sunday papers."
Det Ch Insp Campbell dislikes the media spotlight, and resents having to spend so much time away from the investigation. A highly respected murder detective, he lacks television charisma, although his on-screen performances have become increasingly assured and fluent.
In order to "clarify" or knock down and deny a series of exclusive stories, he has held several off-the-record briefings with crime correspondents to spell out leads that the Yard is not pursuing. He has also repeatedly stressed that his team does have good intelligence, but that if they disclose the details the investigation will be compromised.
The balance between crime reporting and policing is a delicate one. The police frequently need the media to make public appeals on their behalf and to promote their achievements. Note the immediate success last weekend in tracing an 18-month-old toddler. But they are reluctant to give "case- sensitive" information, and many police officers still have a great distrust and dislike of the press.
Scotland Yard is way ahead of many other forces in its openness and media facilities. One major city force in England has a virtual "no comment" policy on any issue.
And so we come to last Thursday's news conference. In one sense the police were using one of their few trump cards; the indentations on the cartridge made headline news. But deciding to go public was also an admission that they had failed to trace the bullet's owner. The timing of the press conference was also interesting; it neatly took the sting from criticism in that evening's Tonight With Trevor McDonald that Scotland Yard had failed to give regular press briefings.
But if the Dando case is to be solved, it looks increasingly as if the breakthrough may come via a member of the public reading a newspaper or watching television, rather than by a great feat of detection.
The writer is crime correspondent of `The Independent'Reuse content