WELLESLEY, Mass. — The serene woods surrounding Morse's Pond usually attract solitary joggers and dog walkers. But on Wednesday a large group, no less quiet and contemplative, marched through the park. They were jurors and court officers, and they had come to examine the area where renowned Boston doctor Dirk Greineder is accused of murdering his wife.

The task of the jurors was made especially difficult because they were told very little about the crime. Escorted by Norfolk County Superior Court Judge Paul Chernoff, defense lawyer Martin Murphy and prosecutor Richard Grundy, the panel was instructed to take in the surroundings and remember key places marked by orange cones — wooded areas, clearings, paths, a sewer grate, a parking place — but was never told what transpired and where.

Showing the jury a crime scene before opening statements is highly unusual. In most cases, tours are scheduled for the end of the trial so jurors can put evidence within a physical context. In this case, possibly because the crime scene is intricate and difficult to describe, both sides agreed to the pre-trial tour. Lawyers had a chance beforehand to describe to jurors what they would see and to what they should pay special attention.

Morse's Pond

"We are going to get an appreciation for what the scene is like because that will illuminate the testimony and that will illuminate some of the physical evidence," prosecutor Grundy explained to the panel.

The all-white jury of 10 men and six women (four of whom will be randomly selected as alternates before deliberation) will have to determine whether Greineder, 60, is guilty of killing his wife Mabel, then 58.

The prosecution claims that the respected doctor and father of three bludgeoned his wife of 31 years to death during a walk in the woods because he wanted more freedom to live a secret life of sexual obsession and trysts with prostitutes. The defense maintains that the couple separated on their walk and that an unknown killer struck while Mabel Greineder was alone.

The doctor is being tried for first-degree murder and faces life in prison if convicted.

After the jury was shown the relevant locations, a special second tour was set up for members of the media, who were given no more information than the jurors. Court documents, witness statements and reported facts about the case, however, explain the significance of certain areas.

The sand pit

One of the key locations, stressed by both lawyers before the tour, is a clearing known as "the sand pit," where Greineder says he and his wife were playing fetch with their dog on the morning of Oct. 31, 1999. The doctor says that his wife injured her back and decided to go back to their vehicle. To do so, she would have had to walk about 100 yards down a path flanked by pine woods.

The wooded path along which Mabel Greineder was killed

On that path, Mabel Greineder was attacked. Her throat was slashed with a knife, and she was beaten repeatedly over the head with a small hammer. Marks on the ground indicated that her body was then dragged a small distance off the path and into the woods.

The sewer grate under which the evidence was found

On another nearby trail, police found a knife, hammer and right-handed glove hidden under a sewer grate. A man who was walking his dog around the time of the murder claims he saw Greineder coming out of this paved path. The man, who is expected to be a key prosecution witness, says the doctor then told him that his wife had been attacked and asked him to call for help.

In the vicinity of the murder scene, several other small paths join with the main trail. The defense is expected to argue that another man lay in wait on one of these forks and ambushed Mabel Greineder. While the prosecutor did not mention these alternate paths during his statements to jurors, defense lawyer Murphy stressed them.

Opening statements are scheduled for Thursday.

The trial is being broadcast on Court TV.