NEW YORK - Juror deliberations began Tuesday in the murder trial of a former nanny accused of stabbing to death two children in her care.

On Monday, Yoselyn Ortega's lawyers told jurors she suffered from an untreated mental illness and hallucinations when she killed Leo and Lulu Krim in their Upper West Side apartment back in 2012.

The defense also said there was no motive for the killings. 

The prosecution argued Ortega was jealous and unhappy, and that she carefully planned out the attack. 

Ortega is charged with two counts of first degree murder and two counts of second degree murder.

She has pleaded not guilty by reason of insanity.