Watched by millions, the final act of a courtroom tragedy

The case against Casey Anthony might have all the ingredients of a daytime soap opera, but the trial which reaches its climax in Orlando, Florida next week is playing more like a summer movie blockbuster.

Each day, hundreds of tourists begin lining up outside the Orange County courthouse shortly after 5am, hoping to get one of 50 seats in the public gallery of an air-conditioned room where Anthony has, since the end of May, been in the dock, accused of killing her two-year-old daughter Caylee and dumping the child's body in a swamp. From time to time, minor scuffles break out in the queue.

Two million Americans are tuning in for gavel-to-gavel coverage of this gripping trial. Their obsession is helping an obscure news channel called HLN suddenly leapfrog CNN and Fox news to the top of the cable ratings. Breathless courtroom pundits such as Nancy Grace and Diane Dimond are revelling in a limelight they haven't enjoyed since the sensational trials of OJ and Jacko.

But with blanket coverage across every branch of the press, and fans excitedly planning "verdict parties" for the case's imminent conclusion, two perennial questions are now rearing their awkward heads: does the glare of tabloid publicity interfere with administration of justice? And do courtroom cameras make for fair treatment of a defendant whose life is, quite literally, on the line?

There are certainly many dramatic layers to the case against Anthony, a 25-year-old single mother whose photogenic daughter Caylee went missing on 16 June, 2008, two months before her third birthday – and whose body was found, with duct tape stuck to the decomposing flesh of her skull, three months later.

Prosecutors, who are seeking the death penalty and have charged her with seven serious offences, including first-degree murder, claim that Anthony used chloroform to render the child unconscious, and then put tape over her nose and mouth and threw her in the boot of a car to suffocate. Several days later, they allege, she dumped the body on unoccupied land near her family's Orlando home.

In the weeks after Caylee's death, Anthony allegedly told her parents, who she lived with, that the child was being looked after by a nanny. Then, according to photos uploaded to Facebook, she spent several nights visiting nightclubs and attending house-parties, in what the prosecution has dubbed a macabre celebration of freedom she had been denied since her daughter's birth. The child wasn't reported missing to police for almost a month.

Helping prosecution efforts to portray Ms Anthony as a sort of scarlet woman is an incident during the police investigation of the case, when an officer was suspended after it emerged that he had exchanged inappropriate text messages with the suspect. The defence, for its part, argues that Caylee drowned in the swimming pool at the family home, and that Casey and her father, George, panicked and decided to cover the death up. They have chosen not to ask Casey, who pleads not guilty to all charges, to take the stand, and in cross-examination their theory has been vehemently denied by Mr Anthony.

A number of side-plots have added to the soap opera nature of proceedings. The identity of Caylee's biological father is not known, for example. Both George and Casey's brother Lee have submitted to DNA tests which have rebutted rumours that the little girl was the unwanted product of an incestuous relationship.

George Anthony has meanwhile been accused of sexually abusing Casey from the age of eight (he denies the suggestion). It has further emerged that in the January after his granddaughter went missing, he considered taking his own life, and even wrote a suicide note which has been presented as evidence in court.

The defence has also attempted to link Caylee's grandmother, Cindy, to the child's death. They have discovered, for example, that she conducted an internet search for "chloroform" around the time of the girl's supposed disappearance.

The defence has also done its best to discredit macabre testimony from several witnesses who claim to have smelled rotting flesh coming from Casey's car, saying it was in fact bags of rubbish which had become overheated in the Florida sunshine.

As the trial reaches its final stages, with closing arguments expected this morning, public opinion is deeply divided about the case. Although the majority of observers believe evidence against Ms Anthony to be compelling, a small but vociferous minority insist she is the hapless victim of trial by tabloid media. One such supporter, a restaurant waiter called Matthew Bartlett, was jailed for six days earlier this week for contempt of court, after making an obscene gesture to prosecutor Jeff Ashton from the public gallery. "It's just another odd aspect of this case," a baffled Ashton later told assembled reporters.

The incident, which might have jeopardised the entire trial, neatly demonstrated how the media circus, stoked by the existence of cameras in court, can interfere with the administration of justice. Courts in 48 American states allow trials to be broadcast (federal courts generally do not) under certain conditions which include obscuring the faces of the jury. And controversy over their existence has been around for almost as long as the moving image.

In 1935, Bruno Hauptmann was sentenced to death for the kidnapping and murder of the aviator Charles Lindbergh's son. The conviction, at a trial broadcast on motion picture newsreels, was the first to raise questions about whether cameras propagate an unfair, anti-defendant climate. Hauptmann protested his innocence even as he was being strapped to the electric chair.

The most celebrated media circus in history, however, surrounded the murder trial of OJ Simpson, who was acquitted of murdering his wife and her lover in 1995. The judge at the so-called "trial of the century" was widely criticised for failing to prevent lawyers from grandstanding. In the immediate aftermath of the case, many judges were reluctant to allow cameras into their courts.

Recent years have seen a gradual rehabilitation of the camera's image, however. And in May, the Master of the Rolls, Lord Neuberger, suggested that they should even be tried in British courts.

Royal Oakes, an attorney and legal analyst for NBC who often represents TV companies wishing to broadcast trials, says the recent Phil Spector case provided evidence that even high-profile cases can pass off without a hitch.

"Sunlight is the best disinfectant. When there is transparency, people behave better. There is more honesty and fairness when they know people are watching. That's the main point to make."

Whether Casey Anthony would agree with his argument will probably depend on the verdict handed down some time towards the end of next week.

Trials by TV

OJ Simpson (25 January 1995 - 3 October 1995)

Charge: Murder of Nicole Brown Simpson and Ronald Goldman

Verdict: Not guilty

The trial of actor and former American football star OJ Simpson was the TV event of the year, if not the decade. The nine-month case drew unprecedented media coverage and remains the most publicised in American history. As many as 142 million people are believed to have watched Judge Lance A Ito deliver a verdict of not guilty on 3 October 1995. Many lawmakers felt the publicity prejudiced the case and judges have been cautious allowing cameras into celebrity trials since.

Louise Woodward (7 October 1997 - 10 November 1997)

Charge: Murder, downgraded to manslaughter at appeal

Verdict: Guilty

Nearly 1.7 million people in Britain watched the final sentencing of the 19-year-old British au pair on Sky, more than watched the 9/11 attacks or coverage of Princess Diana's death. Woodward was accused of killing eight-month old Matthew Eappen, while babysitting him in Boston, Massachusetts. Her supporters watched proceedings live in a pub in her hometown of Elton, Cambridgeshire. She was convicted of second-degree murder, but had her sentence downgraded to manslaughter at appeal and was freed.

Phil Spector (19 March 2007 - 26 September 2007)

Charge: Murder

Verdict: Trial collapses; second trial in 2009 finds him guilty

The record producer famous for working with The Beatles and Tina Turner was accused of killing the actress Lana Clarkson at his home in 2003. In a televised and much talked-about trial, the presence of his new 26-year-old wife, Rachelle, in the courtroom attracted much diversionary media attention. The jury returned a hung verdict and the trial collapsed. Spector''s second trial, in 2009, was not televised, but cameras were allowed to capture his reaction to the guilty verdict.

Michael Jackson (28 February 2005 - 13 June 2005)

Charge: Several counts of child molestation

Verdict: Not guilty

The late king of pop fought off an avalanche of rumours about his conduct with minors, but he faced trial after the family of 15-year-old Gavin Arvizo accused him of child molestation. Judge Rodney Melville banned cameras and issued gagging orders in a bid to stop the trial becoming a media circus. But, so hungry were television networks for courtroom drama that E! staged and broadcast daily re-enactments with actors playing Jackson, the judge and everyone else in the courtroom. Much to the relief of his legions of fans, Jackson was acquitted of all charges.