This is how I think it works.
1) Start by having a bunch of background noise: junk food, chemtrails, vaccines, violence on TV/web.
2) Destroy the families and religion which provide stability for troubled children.
3) Select a traumatized child with a poor support system (single parent, orphan, no friends, etc.)
4) Send the child to get medical help. Give the child a prescription for drugs known to cause anger, personality splits, doziness, or make him easier to control.
5) Add in a professional therapist. Note that unlike general practitioners, therapists do not allow parents into the room. The therapist is alone with the child. Use suggestions or hypnotics to direct the child toward violent behavior.
6) Provide a hypnotic trigger. Cellphones could easily be used to transmit a tone or message.
If you have a troubled child, how do you combat this? Remove as many pieces from their plan as you can. Recruit family, local churches, and friends to support the child, and replace therapists. Feed the child a diet of locally grown, simply cooked food. Consider home remedies such as herbal tea, limiting sugar, yoga. Turn off or heavily restrict the influences of social media. Remove all electronics from the child's bedroom. Establish routines, and limit unsupervised boredom. Find the child a part time job or pay him to do extra chores. Get the child more exercise, play outdoors, and have the child join a sports team. Have the child join clubs or go on supervised outings with healthy influences. Start or volunteer with a club and go with your child. As the child improves, aggressively insist, with medical supervision, that your doctor reduces, or if possible eliminate, the drug prescriptions.