A man convicted in the death and dismemberment of a Bourbon Street dancer is seeking a new trial, citing a history of mental illness and three failed requests for a mistrial during his proceedings.

Terry Speaks is scheduled to be sentenced to life in prison Thursday in the 2013 death of Jaren Lockhart.

But multiple news agencies report that in a motion filed Monday, public defender John Benz argues that Judge Stephen Grefer should have asked Speaks about possible mental illness when the defendant sought to represent himself on the trial's opening day. Benz's motion says Speaks has been hospitalized for mental illness, including a suicide attempt.

Speaks and his girlfriend, Margaret Sanchez, are accused of cutting up Lockhart's body and dumping the remains along the Mississippi Gulf Coast.