Prosecutor Jonathan Laidlaw QC said while the picture was not straightforward, the various pieces of evidence against George were no coincidence.
Laidlaw said prosecutors “do not lack any confidence at all” that the man in the dock was the gunman who shot Dando on her doorstep.
George, aged 48, denies murdering the Crimewatch presenter in Fulham, west London, in April 1999.
In his closing speech to the jury, Laidlaw said it had been from the start a “demanding and exacting case” for the police.
There were no DNA or fingerprint clues and neighbours, unaware of the shooting, had no reason to pay much attention to a man they saw walking quickly away.
“There was no obvious candidate for this killing, nobody with anything approaching a rational motive to kill this woman,” Laidlaw said.
Dando was “happy and content” and had not been the subject of any threats as a result of her work on Crimewatch. Nor had she been the target of a hate campaign or fallen out with any ex-boyfriends, the court heard.
Laidlaw said investigators had to fend off the distractions of “countless theories” about what did happen. There was no evidence to support suggestions that it was a contract killing or part of a terrorist plot, he added.
When Barry George was first asked to provide a statement nearly a year after the murder, not initially as a suspect, then “things began to fall into place”.
A picture of George’s movements around the time was built up, and was followed by a search of his home which disclosed an interest in the military and guns, Laidlaw told the jury.
“The police also found that he was a man obsessed or fascinated by celebrities and interested in, in particular, female presenters and newscasters,” he said.
The trial was adjourned until today.