NORWALK, Conn. – By posh Greenwich standards, the single-story, brick courthouse could pass for a guest bungalow or a vintage car collector’s spare garage. But Tuesday, downtown Norwalk’s courthouse will receive more limelight than any “Lifestyles of the Rich and Famous” episode.

It will be the setting for the trial of Kennedy cousin Michael Skakel, who is charged with killing his Greenwich neighbor and friend Martha Moxley 27 years ago, when they both were 15.

The trial, which court officials expect to take five weeks, will feature a blend of celebrity and scandal. Some Kennedy relatives are expected to fill the 173-seat courtroom to show support for the now 41-year-old nephew of the late Robert F. Kennedy. Defense attorney Michael Sherman is expected to implicate as the killer a tutor who began working for the Skakels the day Moxley was beaten to death. He also might try to pinpoint the time of the murder at 10 p.m. to show Skakel wasn’t there.

“With the high caliber of jury we have,” said Sherman, “I think they will be truly convinced he is not guilty.”

But prosecutors say they have their own ammunition, namely Skakel’s alcohol and discipline problems. Their case is expected to rest on testimony of at least two classmates to whom Skakel allegedly confessed at the Elan School, a Maine boarding school for adolescents with emotional problems. Prosecutors may present evidence created by Skakel including a book proposal in which he details his “full-blown, daily-drinking” alcoholism by age 13 and the murder of his “neighbor and new friend of mine, Martha Moxley.”

“There’s this theme in the trial that a lot of evidence used against Michael was generated by himself,” said Timothy Dumas, author of “A Wealth of Evil: The True Story of the Murder of Martha Moxley in America’s Richest Community.”

On Oct. 30, 1975, Moxley headed out from her 26-room mansion in Greenwich’s exclusive Belle Haven neighborhood for a “mischief night” with friends. The next morning, Moxley’s bludgeoned body was found under a Ponderosa pine tree in her back yard. Police say she was killed with a golf club from a set found in the Skakel home located diagonally across Walsh Lane from the Moxleys.

Police first suspected Skakel’s 17-year-old brother, Tommy, because he was the last person seen with Moxley. Then the case shifted to tutor Kenneth Littleton in 1976, after he failed a polygraph, said Dumas.

In the early 1990s, father Rushton Skakel hired a private investigative firm, Sutton Associates, to clear his sons’ names. Instead, their findings placed Tommy at the scene of the crime for the first time, Dumas said. In 1995, a Newsday reporter got the private reports and alleged confession stories from Michael’s Elan classmates started appearing.

In 1998, a Superior Court judge started a one-person grand jury investigation into the murder. On Jan. 19, 2000, Skakel was charged after an investigation produced enough evidence to warrant his arrest. Since Skakel was 15 at the time of the killing, Skakel’s attorney fought for him to be tried as a juvenile.

Last spring, Superior Court Judge John F. Kavanewsky Jr. found Skakel should be tried as an adult, based on his romantic links to Moxley, the golf club and his alleged confessions to his classmates.

It took the court three weeks to pick Skakel’s 16-member jury, which includes a hotel executive, an excavator and a lawyer. Also seated were a police officer who was assaulted by one of Skakel’s attorney’s clients and a woman whose friend’s father was murdered and whose mother became friends with Martha Moxley’s mother, Dorthy. Both said they could be impartial.

The plot twisted again after a Stamford newspaper reported April 28 that Skakel was forced to leave a private boarding school in Vermont in 1978 because he threatened a teacher’s wife with a ski pole.

But legal experts say it’s going to be difficult to convict Skakel for a 27-year-old crime.

“It’s a tough case for the prosecution because they don’t have a fresh case,” said Howard Varinsky, a jury consultant based in Oakland, Calif., who has worked on the cases of Timothy McVeigh and New York subway gunman Bernhard Goetz. “The more serious the charge, the jury tends to get very, very conscientious because they know they’re talking about someone going away for life.”

In Greenwich, residents say that for many years the case was rarely discussed. The Skakels and Moxleys moved away.

In downtown Norwalk, the trial has created more hassle than intrigue. Over the whir of dryers at the Wash-n-Dry across from the courthouse, manager Arti Singh unloaded her fears of losing customers who cannot park because of network television trucks.

“I don’t like it being that he’s so close. It’s a scary thing,” she said. “Everybody says he is going to get off because he is a Kennedy.”