Prosecutors revealed in court on Monday that they intend to ask a grand jury to consider a charge that Ryan Wesley Routh attempted to assassinate former President Donald Trump.

The federal judge at the West Palm Beach hearing denied bail, ruling that Routh must remain detained pending the resolution of the charges, calling him a serious flight risk and danger to the community.

Routh, 58, has already been charged with possession of a firearm as a convicted felon and possession of a firearm with an obliterated serial number for the incident that took place at Trump International Golf Club on Sept. 15.

Routh did not enter a plea for his initial charges and his arraignment is scheduled for Sept. 30.

On Monday, prosecutors outlined new details about their investigation and said there is “probable cause to support additional charges which can and should be considered by the court.”

Assistant U.S. Attorney Mark Dispoto said the government is prepared to “ask a grand jury to consider a charge that the defendant attempted to assassinate Trump,” which carries a “maximum sentence punishable by life in prison.”

Routh possessed a list that included dates from August to October of venues where Trump had appeared or was expected to be — and is suspected to have traveled near the golf course and Trump’s Mar-a-Lago resort multiple times in the month leading up to his arrest, prosecutors said in a detention filing.

In their memo, prosecutors further revealed that Routh allegedly sent a letter “several months prior” to his arrest to a civilian witness that stated, “This was an assassination attempt on Donald Trump but I failed you.”

Trump was playing golf on the course when a Secret Service agent spotted a gun barrel poking out from the tree line near the sixth green, according to investigators.

Dispoto on Monday went into detail describing the fence surrounding Trump’s golf club and the moment the Secret Service advance agent saw the barrel of a rifle.

“What they found, your honor, was nothing short of a sniper position,” Dispoto said, equating it to something seen in “the movies or a war zone.”

The government argued the sole reason Routh was in West Palm Beach on Sept. 15 and the proceeding month was “for one reason and one reason only and that was to kill the former President of the United States.” Dispoto said if it wasn’t for the quick work of the Secret Service, “the defendant may very well have succeeded.”

An FBI special agent’s “ballpark” estimation was that the distance between where Routh is alleged to have been positioned on the fence line, to the green on the sixth hole of the course, was 100 feet — 32 yards or so.

“This was an easy shot. He was approximately 12 to 15 minutes away from arriving,” Dispoto said of Trump’s positioning on the course at the time. Dispoto said there were no obstructions to Routh’s “snipers nest” should Trump have arrived at the sixth hole.

FBI special agent Christopher Hull said this view from the fence line to the sixth hole was “generally an open view” with “very minimal” obstructions.

“I do not believe anything would have obstructed” the view from the fence line to the sixth hole, Hull said. Hull said he examined other areas of the fence line, and every other area would have been “a blocked view.”

The evidence, Dispoto said, “clearly demonstrates a month-long plan to assassinate the former president.”

According to the government, the rifle Routh is alleged to have had contained a round in the chamber, which indicated it would have fired with the pull of the trigger. The rifle’s extended magazine contained a total of 11 rounds, the government said.

Prosecutors also revealed that shortly after Routh was arrested, he spoke with a female acquaintance and indicated that he was on a recorded line. Routh said to the person he was sorry.

The person, whose identity was not revealed by prosecutors in court, responded to Routh by saying: “I am processing the most horrific thing you could have done.” Routh, according to the government, responded by apologizing again.

Magistrate Judge Ryon McCabe said the weight of the evidence the government presented — as to the two gun charges — is “strong” and further noted that the evidence the government presented of potential additional charges is even greater.

The judge said Routh’s alleged movements and locations leading up to his arrest constitute an “apparent effort to stalk [Trump] for 30 days in an attempt to assassinate him.”

The investigation is ongoing and the FBI has been going through Routh’s social media and criminal history and speaking with family members to get more clues.

As authorities try to unravel the motive and details of the case, sources said investigators were looking at whether Routh was frustrated with Trump’s position on Ukraine.

Trump on Monday said the initial charges against Routh, which include the gun charges, were a “slap on the wrist” and appeared to criticize the FBI and DOJ’s handling of the case.

Investigators further revealed on Monday that three days after they arrested Routh, a civilian witness contacted them with information that Routh had dropped off a box at their residence several months ago that contained “ammunition, a metal pipe, miscellaneous building materials, tools, four phones, and various letters.”

“One handwritten letter, addressed to “The World,” stated, among other things, “This was an assassination attempt on Donald Trump but I failed you,” the filing said. “I tried my best and gave it all the gumption I could muster. It is up to you now to finish the job; and I will offer $150,000 to whomever can complete the job.”