I always hate these stories. The mother obviously is wrong but she nevertheless is a mother who is dealing with the horror of her son committing a terrible crime. Of course she is going to defend him. I usually will give these mothers and fathers a couple weeks to say whatever they want and get it out of their system before I start to criticize them.
Her “there is another side to the story” does not make any sense. What other side is there? He went into the business and decapitated a former coworker and would have done it again to another coworker who he stabbed if he had not been stopped by the security guard who shot and wounded him. The only just punishment for him is the death penalty