A federal judge on Monday ordered Ryan Routh, the man accused in connection with an assassination attempt against former President Trump earlier this month, held in custody. 

Magistrate Judge Ryon McCabe granted the government’s request to detain Ryan Routh pending the resolution of charges during a court hearing in Florida. 

Prior to the hearing, the Justice Department asked the United States District Court for the Southern District of Florida to keep Routh in pretrial detention. McCabe said federal prosecutors met their burden and the weight of the evidence was strong.

TRUMP ASSASSINATION SUSPECT WROTE CHILLING LETTER MONTHS BEFORE GOLF COURSE PLOT

Routh has been charged federally with possessing a gun with a scratched-out number and with possessing a gun illegally as a felon, though more serious charges are likely pending. 

Federal prosecutors also told the judge that the government intends to ask a grand jury to indict Routh on the much more serious charge of the attempted assassination of Trump.

In addition, prosecutors said they have an audio recording of a recent jailhouse phone call from Routh to a female friend. During the call, Routh said he was “sorry,” while the friend said she was still “processing” the worst possible thing he could have done. 

Prosecutors said Routh then apologized a second time. 

Routh will likely face additional charges in the coming days, which could include aggravated assault for allegedly pointing the rifle at a U.S. Secret Service agent and making threats against a former president, State Attorney Dave Aronberg previously told Fox News Digital. 

Routh is accused of targeting the 45th president as he waited about 12 hours outside a golf club where Trump was playing a round. 

McCabe said it appeared Routh was stalking Trump for 30 days and had a passport with him when he was caught along with a phone, which had a search history of how to travel from Palm Beach to Florida.

Federal prosecutor Mark Dispoto described Roth’s location next to the sixth hole, with the gun and bags as “nothing short of a sniper’s nest.” Dispoto also said the two bags next to the gun, which had plates, or tiles in them which were bulletproof, was part of an effort to protect himself if Secret Service agents returned fire.

RAPPER 50 CENT REVEALS WHY PEOPLE ‘IDENTIFY’ WITH TRUMP FOLLOWING ASSASSINATION ATTEMPT

Florida Gov. Ron DeSantis said in a press conference last Tuesday that Florida will pursue more charges against Routh and that his offense should merit life in prison.   

On Monday, the Justice Department also released a chilling letter written by the suspect. 

The Justice Department obtained the letter from a witness who says they received it inside a box delivered to them by Routh several months prior to the assassination attempt. Authorities say the witness opened the box only after hearing Routh was suspected in the attack. 

The box contained several handwritten letters as well as ammunition, among other things. One of the letters, addressed “Dear World,” discussed the assassination attempt. 

Routh had written in the letter that he had failed and that he would give $150,000 to anyone who could finish the job. 

CLICK HERE TO GET THE FOX NEWS APP 

In a court filing, prosecutors also referred to Routh’s conviction for possession of a weapon of mass destruction in 2002. They told McCabe that the device was a “binary explosive device” with a fuse.

Fox News’ Anders Hagstrom, Jake Gibson and David Spunt contributed to this report.