Bizarre "explanation" for assassination of Minnesota democratic house member

[lostnfound]

1. Status - indicted on 6 federal charges on July 15th, pled not guilty on Aug 7 (links)

Can anyone explain why these are federal charges?
https://www.justice.gov/usao-mn/pr/vance-boelter-indicted-murders-melissa-and-mark-hortman-shootings-john-and-yvette-0

This case is the result of an investigation conducted by the FBI, Minnesota Bureau of Criminal Apprehension, ATF, Brooklyn Park Police Department, Minneapolis Police Department, Hennepin County Sheriff’s Office, Champlin Police Department, and New Hope Police Department, together with several other state and local partners. The National Security Division’s Counterterrorism Section also assisted in the investigation. This investigation has proceeded with the U.S. Attorney’s Office in strong partnership with the Hennepin County Attorney’s Office

Pled not guilty; Pam Bondi to decide on seeking death penalty; letter to Kash Patel
https://www.mprnews.org/story/2025/08/07/vance-boelter-enters-plea-in-minnesota-lawmaker-hortman-shooting-case

Acting U.S. Attorney Joe Thompson said in July that that a decision on whether to seek capital punishment is months away and will ultimately be made by Attorney General Pam Bondi with input from Minnesota federal prosecutors and the victims’ families.

In addition to Atwal, a federal public defender based in Minneapolis, Boelter’s defense team includes Las Vegas-based federal defenders Kimberly Sharkey and Ryan Norwood. Sharkey is chief of the death penalty unit in the federal public defender’s office.

When they announced the indictment, federal prosecutors released a rambling handwritten letter they say Boelter wrote to FBI Director Kash Patel. In it, Boelter allegedly confessed to the June 14 shootings of Melissa Hortman and her husband, Mark, but it does not make clear why he targeted the Hortmans or Sen. John Hoffman and his wife, Yvette, who survived.