Former mixed-world champion Cedric Marx, nicknamed "Spider-Man", faces the death penalty after being accused of killing and burying two people in a rural grave.
Marx, 45, was classified by police in Minnesota as "extremely dangerous" after he escaped in August from a prison bus and was re-arrested after a nine-hour hunt in February.
His murder charges date back to January 3, when his former girlfriend Gina Scott, 28, and her boyfriend, Michael Soeren, 32, were killed in a Texas home. She was later discovered by the police.
Marx refused to admit the crime, and the court sent the evidence for analysis and DNA testing on all physical evidence. The next trial is expected in mid-January.
Marx is one of the most prominent and fiercest fighters in the average weight of mixed martial arts, winning 31 wins during his career, including 13 knockout.