A murder trial involving a 27-year-old mother accused of killing her 5-year-old son by poisoning him with salt began on Monday in Westchester County, New York.

Lacey Spears of Scottsville, Kentucky, is charged with depraved murder and manslaughter in the death of her son, Garnett-Paul Spears. Not only is Spears accused of purposely poisoning the boy, but prosecutors say she also documented his health decline on social media.

On the Internet, Spears presented herself as a devoted mother and mommy blogger. However, in reality, "this mother was intentionally feeding her child salt at toxic levels," prosecutor Doreen Lloyd said at her arraignment, according to The Associated Press.

Prosecutors also believe the single mother administered salt through a feeding tube into Garnett's stomach while he was at the Westchester Medical Center in White Plains, New York, reports Time.  As a result, the boy's sodium levels became lethal, leading to a swollen brain, seizures and eventually death.

Spears chronicled her son's life, many hospital visits and sickness online. She also shared 28 posts documenting the last 11 days of his life.

"My Sweet Angel Is In The Hospital For The 23rd Time," Spears tweeted on Nov. 9, 2009, adding a sad-faced emoticon and "Please Pray He Gets To Come Home Soon."

"Garnett the great journeyed onward today at 10:20 a.m.," Spears wrote on the day her son died.

Jury selection began Monday at the courthouse.

It is likely the messages Spears shared on Facebook, Twitter and MySpace will be introduced as evidence during the trial.

State Supreme Court Justice Robert Neary also ruled prosecutors can use evidence that Spears researched the dangers of sodium in children and the properties of iodized salt on her iPhone.

Spears, originally from Decatur, Alabama, was living in Chestnut Ridge, New York, during the time of her son's death. She then moved to Kentucky before she was arrested in June.

If found guilty, Spears will face 25 years to life in prison.