Muth, 47, has maintained his innocence in several letters to the court. He will be expected to formally enter a plea when he is arraigned on the charge March 14.
The indictment also charges two special circumstances which, if Muth is convicted, would add time to his sentence. The charges are that the murder was “especially heinous, atrocious or cruel” and that Drath, the victim, was “especially vulnerable due to age.”
Drath was 91 when she was killed.
A spokesman from the US Attorney’s Office said that if convicted of the charge, Muth could be sentenced to life in prison without parole.
Read the indictment below.