This was the final straw. Diane Payton felt compelled to murder her son to prevent him from killing more people. McCoy demands a hearing in chambers. He is outraged the defense is effectively changing their plea from not guilty to guilty by justification. He demands the defense case be thrown out, but the judge refuses. McCoy's position begins to look weak. Southerlyn confronts Hartley, angry that Hartley played on her sympathy to get the medical records introduced. She accuses Hartley of being less motivated by love for her family and more by the boost it would provide to her career. The next day McCoy cross-examines Diane Payton and asks why she didn't inform the police of her son's suspected actions, or call the police herself after she killed him. Finally, McCoy asks that if Diane Payton knew her son was a homicidal man with schizophrenia, why did she willingly give him the keys to her car? The jury finds Diane Payton guilty of second-degree murder, but the jury foreperson asks if any jail time is necessary. Themes Mother and child relationship Self-interest being a motive before the welfare of others at all cost Guest stars Charissa Chamorro as Kay Hartley Ellen McLaughlin as Diane Payton Janet Zarish as Caroline Milius Martin Kildare as Ronald Milius Leslie Hendrix as Dr. Elizabeth Rodgers Mark Alan Gordon as Dr. David Trask Don Billett as Judge Ed Richter References External links "Law and Order" Mother's Day at imdb.com Law & Order episodes 2003 American television episodes Washington Heights, Manhattan Mother's Day