Aaron Hernandez’s lawyers filed paperwork Thursday to appeal his first-degree murder conviction.

In the appeal, Hernandez’s attorneys argued jurors relied on “improper speculation, conjecture and guesswork” to convict Hernandez for first degree murder in the June 2013 death of Odin Lloyd, according to Brian Fraga of The Herald News.

His attorneys also claimed prosecutors failed to produce any evidence “that proved Hernandez acted with malice or intentionally participated in Lloyd’s murder.”

The former New England Patriots tight end was convicted April 15.

Earlier this week, Hernandez was charged with intimidating a witness related to a 2012 double murder in Boston’s South End.

Thumbnail photo via Brian Snyder/Associated Press