NORWALK, Conn. – There are no eyewitnesses to Martha Moxley’s 1975 murder. There is no DNA or other high-tech evidence to link Kennedy cousin Michael Skakel to the crime.

Closing arguments, important in any murder trial, may prove critical in the case against Skakel, based largely on wide-ranging circumstantial evidence.

Skakel is accused of beating Moxley to death with a golf club when both were 15-year-old neighbors in a wealthy gated community in Greenwich. The golf club used in the murder was matched to a set owned by Skakel’s mother. Skakel is a nephew of Ethel Kennedy, widow of Robert F. Kennedy.

Closing arguments are scheduled for Monday. Prosecutors will try to convince the jury of Skakel’s guilt based on statements or admissions he made over the years to classmates, a Greenwich hairdresser, a family chauffeur, a childhood friend and an author.

“Unfortunately we don’t have a smoking gun,” said John Moxley, the victim’s brother. “I think the case is going to be won or lost by the strength of the closing arguments.”

Prosecutors need to weave the testimony together, to the point where jurors can visualize the crime, said John Connelly, state’s attorney in Waterbury.

“When you put all those pieces together the picture you see is Michael Skakel with that golf club in his hand, standing over that 15-year-old girl,” Connelly said.

But Skakel’s defense argued in opening statements that the pieces don’t fit. They say Skakel was miles away at a cousin’s home at the time Moxley was killed. They deny Skakel confessed and have presented witnesses who testified that Skakel was repeatedly beaten and berated at a school he attended in the late 1970s in an attempt to get him to confess.

In any trial, final arguments offer attorneys a chance to address the jury directly in an effort to bring together weeks of testimony. The statements are not evidence, but they are the last words jurors hear from attorneys before deliberating.

“Jurors can’t help but be persuaded by final arguments,” said Hugh Keefe, a defense attorney in New Haven. “Many lawyers think it’s the most important part of the trial.”

Final arguments become more important in complicated cases, Keefe said.

Aside from two alleged admissions, much of the testimony involves what prosecutors have called a consciousness of guilt. A family driver testified that Skakel in 1977 said he had done something very bad and had to kill himself or get out of the country. The hairdresser alleged Skakel said while getting a haircut that he had “killed before.”

Others have testified that Skakel said he was not sure what happened the night Moxley was murdered because he was so drunk. Skakel himself, in a 1997 interview for a book proposal, said he went back out the night of the murder to the Moxley property.

While trying to win over the jury, prosecutors must exercise caution in not overstating the evidence presented.

Connecticut’s two highest courts have recently granted new trials to three men – an alleged arsonist, a policeman accused of a brutality cover-up and a teen-ager charged with manslaughter – because prosecutors’ closing arguments went too far.

Not everyone believes closing arguments are crucial. The final statements might sway one or two jurors who are undecided, said Richard Brown, an attorney in Hartford and former president of the criminal justice section of the Connecticut Bar Association.

“Most of them are going to come into court with a pretty good idea where they’re going,” Brown said. “At this point typically the die is cast.”