LINCOLN COUNTY, Oklahoma - The manslaughter case in the death of a Sac and Fox police officer is one step closer to trial. 

Two years ago, Officer Nathan Graves was killed in a head-on collision while on patrol on Lincoln County.

The Graves family and his fellow officers packed into a courtroom for what would otherwise be a fairly routine hearing.

To their relief a trial date was set for June 10th, 2019.

"There's light at the end of the tunnel, we're ready for court...we've been ready," said Janet Graves.

Graves has been seeking justice for her husband since the crash on January 24, 2017.

According to law enforcement officials, it was around 6 a.m. when Graves was headed south on Highway 99 near County Road 750, and Justin Henley, 21, was driving northbound in his pickup.

Investigators say Henley tried to pass a car in a “no passing zone” and crashed into Officer Graves.

"We intend to prosecute this case to the full extent of the law...this case has gone on long enough," said Lincoln County Assistant District Attorney Greg Wilson.  

Prosecutors charged Henley with first degree manslaughter. He's accused of making more than one unlawful pass before the collision.

Henley's attorneys John Hunsucker and David Slane declined to comment at this point in the case.

However, court records indicate they are questioning if Henley can get a fair trial in Lincoln County.

The defense filed a motion for a change of venue.

In the motion, they claim the publicity from donation drives and memorials for the fallen officer could taint the jury pool.

A recent petition drive and "Officer Nathan B. Graves Memorial Highway" signs on Highway 99 are also noted for the potential to prejudice potential jurors.

"We don't think there is anything about this case or the involvement of a Sac and Fox Tribal Police Officer that causes this case not to be done right here in Lincoln County," Wilson informally responded.

The court is set to hear the motion and state's response on June 4th, 2019.

Stay with News 9 for any developments.