By the end of the day, eight jurors were in place.
The start of the trial came three years after Peterson was charged. He has been in jail since that time.
During the jury selection process, the court could be challenged to find jurors who have not formed opinions about the high-profile case.
Eight years ago, Savio was found dead in a dry bathtub in her Bolingbrook home. Her death was ruled an accident at the time.
Three years later, however, Drew Peterson's fourth wife, Stacy, went missing, and Savio's case was reopened. Her body was exhumed, and her death was reclassified as a homicide.
The unknown Bolingbrook police sergeant became known and relished in the publicity as his story started to unfold.
Dressed in a grey suit, the former Bolingbrook sergeant appeared in court with a short cropped haircut and his mustache shaved off. He stood up and introduced himself to a pool of 40 jurors by saying, "Good morning, ladies and gentleman, I'm Mr. Peterson."
"Obviously, he is nervous, who wouldn't be in a situation like this, probably the most important event in his lifetime. But you know, he's still strong, he's confident, he knows he didn't do anything wrong," said Joel Brodsky, defense attorney.
A jury pool of over 200 people was selected almost three years ago. Back then, they were ordered to ignore all media coverage of the case. Many said on Monday they have stuck to that order. Others admitted they had watched all or parts of made for TV movie about Peterson.
Discussions in court Monday focused on the issue that has delayed the trial for so long: hearsay evidence.
Before jury selection began Monday, Judge Edward Burmila refused the state's request to allow eight hearsay statements into the trial. However, the judge left open the possibility that he will rule on hearsay statements as they come up in the trial.
Defense attorneys were against allowing the hearsay evidence, saying Peterson is on trial for the murder of Kathleen Savio only and has not been charged in the disappearance of Stacy Peterson.
Both sides must rely heavily on testimony because there is no physical evidence, such as DNA, linking Peterson to the crime.
Peterson's attorneys called their client the ultimate jury consultant, indicating Peterson will be crucial in selecting jurors from his home county.
The defense lawyers did most of the questioning, asking jurors about their spouses, children, education, even if they had any bumper stickers on their cars.
"The important thing when you question a jury is to learn their biases and prejudices, not to find out how they would rule on the case but to find out what makes them tick," said Steve Greenberg, defense attorney.
The defense attorneys said the potential jurors' opinions about Drew Peterson's personality will not matter.
"Jurors do not convict people because they are jerks. Otherwise, there would be a lot of people in jail. Most people would be in jail," Brodsky said.
"Most of the people we represent are not generally likeable people. That has nothing to do with it. They're not going to get an instruction from a judge that says convict them because you do not like them," said Greenberg.
Jury consultants say the defense is looking for anyone who wants a smoking gun in this case because there is none, while prosecutors are looking for a jury who can connect the dots.
"A good juror is going to shift the burden and have it be up to Drew Peterson and his defense team to explain what happened," said Alan Tuerkheimer, jury consultant.
Attorneys for the prosecution did not speak to reporters before entering the courthouse.
Jurors were instructed to fill out an updated questionnaire before questioning began. By the end of the day, eight jurors had been chosen.
By the end of the week, 12 jurors and four alternates should be in place. Opening statements should begin next week on Tuesday.