The guilty plea comes just seven months after the shooting that killed five people,and spares victim’s families and survivors a long and potentially painful trial.
The Stay Safe book,given to primary school students in the Dallas area,advises pupils to “run,hide,fight” if a gunman enters their building.
The billionaire suggested revelations about the shooter’s background could be a psychological operation in which the public is misled about the real details of the shooting.
This latest mass shooting comes amid a shocking surge in gun killings.
Interior Minister Bratislav Gasic described the country’s second mass shooting in 48 hours as a “terrorist act”.
Experts blame a cocktail of factors - including a growing sense of danger - for a spate of shootings around homes.
A Texas man went next door with a rifle and began shooting his neighbours after the family asked him to stop firing rounds in his yard because their baby was sleeping.
Among those killed was Phil Dowdell,a high school senior who planned to play college football,and who was celebrating his sister’s 16th birthday.
A bank building in downtown Louisville,Kentucky,has become the scene of America’s latest mass shooting.
“We called for you all to ban assault weapons,and you respond with an assault on democracy,” said representative Justin Jones before being kicked out of the Tennessee House of Representatives.
Representative Jamaal Bowman,a former middle school principal,told reporters that Republicans were “gutless” for not backing gun control laws after this week’s shooting.