TULSA, Oklahoma - One of the brothers charged with five counts of first-degree murder in the deaths of their parents and three siblings in Broken Arrow has a court appearance scheduled Tuesday.

Court records show a status hearing for Michael Bever. He is the younger of the two brothers.  The older brother, Robert, pleaded guilty in 2016 to the crimes and is serving five sentences of life without parole.

Michael's trial has been delayed several times and is currently set for April 2018. His defense is claiming insanity. He's already had one psychological evaluation on the defense's side.

The prosecution is now asking for an evaluation by their experts.

"We think basically that fair is fair," said Tulsa County District Attorney Steve Kunzweiler. "We want the ability to inquire into the same areas that their expert was able to inquire into."

Earlier this year, Michael's attorneys produced a report saying Michael, who was 16 at the time, was under the influence of his older brother Robert, who was 18. 

That report claimed Michael wasn't able to form "intent" to commit the crimes.