OKLAHOMA CITY - Justin Dougherty sat down with Richard Glossip’s defense attorney to talk about the case and the upcoming Investigation Discovery Channel docu-series, “Killing Richard Glossip.”

Glossip stands to be the next man executed by the state of Oklahoma. He's been found guilty for plotting the 1997 murder of Barry Van Treese. He's has also exhausted all of his appeals. 

His attorney Don Knight says this series is their last hope. 

After multiple questions surrounding the state's execution protocol, all executions have been on hold since late 2015.

Episodes will air April 17 and 18.