Johnson's lawyers and the prosecution set the table for the 12-person jury and three alternates.
Prosecutor Elisa Ramunno told jurors Johnson ran off to another state with the child because the baby's father, Logan McQueary, had broken up with her.
Ramunno said that the young mother had tried unsuccessfully to put her son up for adoption against his father's wishes.
Johnson wiped away tears when the prosecutor said Gabriel was part of his mother's game of retaliation.
"Gabriel Johnson was a pawn. He was a tool," Rumunno told the jury. "He was a piece in a game and the object of that game was to keep Gabriel Johnson from Logan McQueary. It was to retaliate against Logan McQueary for breaking up with her and her intent was to place him in fear for safety of his son."
Johnson's attorney, Marc Victor, said he won't dispute many facts and added that the case wasn't about whether jurors like his client.
"This case isn't about whether or not you like Elizabeth Johnson," Victor said. "It doesn't matter to me whether you like Elizabeth Johnson or not. My job is to do my best to get you to focus on the elements of the crimes charged."
Johnson is charged with kidnapping and custodial interference in the case of her missing son, who was 8 months old when last seen in December 2009.
Johnson's story has changed since the ordeal began.
Tuesday, September 2 2014 8:58 AM EDT2014-09-02 12:58:48 GMT
Scottsdale firefighters rescue dog from irrigation ditch
Labor Day proved to be unique opportunity for firefighters from Scottsdale Engine 601. The crew was driving south on Pima Road approaching McDowell Road when they noticed a dog in an irrigation ditch.More >
Labor Day proved to be a unique opportunity for firefighters from Scottsdale Engine 601.More >
Monday, September 1 2014 8:39 PM EDT2014-09-02 00:39:57 GMT
Search for missing boater underway at Lake Pleasant
A massive search involving divers, underwater robots and cadaver dogs ended Monday afternoon after the presumed drowning victim they were looking for was found alive near a marina at Lake Pleasant.More >
The boater, Bradley Johnson, 31, told Maricopa County sheriff's deputies that he was drunk and disoriented when he swam to shore on Sunday night following some sort of fight aboard the vessel.More >
For some, it may be hard to believe that nine years have passed since Hurricane Katrina made landfall and left major devastation in Louisiana and Mississippi. Most people will never forget where theyMore >
Friday marks nine years since Hurricane Katrina made landfall, causing major devastation in Louisiana and Mississippi.More >