New Details in Grand Jury Investigation

New details are emerging about a grand jury investigation into the Tulsa Police Department.  Fox 23’s Douglas Clark has more. 
 
A source close to the investigation tells Fox 23 the probe centers around a multi-million dollar drug trafficking operation. 
 
The source says about 15-20 people, including law enforcement officials are involved.  The source says the investigation involves false testimony and mishandling of confiscated drugs and drug money.  The source said witnesses in certain drug cases were coerced into lying on the witness stand and were coached on what to say, in order to help ensure convictions.
 
But the source says this is just a small part of this ongoing investigation.  All parties involved are under a gag order.