Luigi Mangione has pleaded guilty to federal stalking charges in the killing of UnitedHealthcare chief executive Brian Thompson.
Mangione entered the plea at a hastily scheduled hearing in Manhattan federal court, which is ongoing.
This resolves one of two cases against him in connection with Mr Thompson’s death.
Mangione is scheduled to go on trial on September 8 on state murder charges.
With his guilty plea in federal court, his lawyers could seek to have the state case thrown out on double jeopardy grounds.
Authorities allege Mangione stalked Mr Thompson, 50, then shot him outside a New York City hotel on December 4 2024, as the executive walked to UnitedHealth Group’s annual investor conference.