A federal grand jury on Tuesday indicted the man accused of showing up at one of former President Trump’s golf courses with a rifle on charges of attempting to assassinate a major presidential candidate.  Ryan Routh, 58, now faces a total of five charges. The indictment marks a significant escalation in the case and comes after prosecutors revealed that Routh allegedly wrote a letter months beforehand detailing his plans.  He faces up to life in prison.  Routh has remained in custody since his arrest shortly after the Sept. 15 incident, when he purportedly waited for roughly 12 hours on the perimeter of Trump’s West Palm Beach golf course until a Secret Service officer noticed him. Prosecutors initially filed a criminal complaint charging him with two firearms offenses.  The indictment marks Routh's first time being formally accused of deliberately attempting to kill Trump. He will be arraigned Monday. He also faces charges of assaulting a federal officer — the Secret Service agent — and possessing a firearm in furtherance of a crime of violence.  “Violence targeting public officials endangers everything our country stands for, and the Department of Justice will use every available tool to hold Ryan Routh accountable for the attempted assassination of former President Trump charged in the indictment,” Attorney General Merrick Garland said in a statement.   “The Justice Department will not tolerate violence that strikes at the heart of our democracy, and we will find and hold accountable those who perpetrate it. This must stop,” the statement continued.  Court records show the case was randomly assigned to U.S. District Judge Aileen Cannon, a Trump appointee who tossed the former president’s classified documents criminal case earlier this year.  The golf course incident marked the second recent attempt on Trump’s life. A gunman shot Trump’s ear while he was speaking at a July rally in Butler, Pa., before being killed by a Secret Service sniper moments later.  Routh, however, allegedly fled his hideout upon being spotted by the Secret Service agent on Sept. 15, leaving behind two bags, a loaded rifle with a scope and other items. Law enforcement later arrested him as he was attempting to drive north on I-95.  Prosecutors revealed Monday that Routh purportedly detailed his plans to assassinate Trump, and predicted it would fail, in a letter written months earlier.  “Dear world, this was an assassination attempt on Donald Trump but I am so sorry I failed you. I tried my best and gave it all the gumption I could muster,” the alleged letter reads.    Prosecutors have also indicated Routh’s phone pinged cell towers in the areas near the golf course and Trump’s Mar-a-Lago residence in the month before the incident. Updated 7:22 p.m.