Multiple high-ranking Republicans have admitted it was a coup attempt.It's not actually a book. Rather, the US constitution. Treason. While it rarely actually results in a death sentence it can.
US Constitution Article III said:§3 Treason against the United States, shall consist only in levying War against them, or in adhering to their Enemies, giving them Aid and Comfort. No Person shall be convicted of Treason unless on the Testimony of two Witnesses to the same overt Act, or on Confession in open Court. The Congress shall have Power to declare the Punishment of Treason, but no Attainder of Treason shall work Corruption of Blood, or Forfeiture except during the Life of the Person attainted.
It says nothing about trespassing in the Capitol being "treason".
And note that trying to overthrow the government is "levying War against them". Even a palace coup doesn't change that.