Lacey Spears, who was convicted by a jury for killing her five-year-old son, was sentenced to 20 years to life in prison by a New York court.

Spears, 27, was convicted in February for second-degree murder. She had killed her young son by slowly poisoning him with salt through a feeding tube since infancy. The boy, Garnett, died in 2014 after over 20 serious visits to medical facilities.

The mother had been consistently active on social media and blogs sharing the life of her difficulties with her son’s declining health, according to International Business Times.

Although she could have received the maximum sentence of 25 years to life, the State Supreme Court Justice Robert Neary did not impose it.

Neary said Spears’ crime was “unfathomable in its cruelty” and brought her son “five years of torment and pain.” But he said he was not imposing the maximum penalty of 25 years to life because “one does not have to be a psychiatrist to realize you suffer from Munchausen by proxy,” according to the New York Times.

The syndrome is a psychological condition where caregivers injure children, not in order to kill them, but to create a situation that requires or appears to need medical attention.

Spears’ attorneys did not use the condition as a defense at her trial, and the prosecution did not seek to assert that her actions were a result of the condition.

Prosecutors said that due to the severe, involved and calculated planning by Spears over the years, they were confident that she had not lost touch with reality.

Assistant district attorney Doreen Lloyd said: “She continued to portray him as a sick child for her own bizarre need for attention.”

“She used that feeding tube as a weapon to kill him,” she added.

Spears did not testify at her trial and did not show any emotion during sentencing.