SPRINGFIELD, Mo.- The bench trial for Derik Osborn began Monday. Osborn is accused of killing his pregnant girlfriend at the Kelly Greens apartments in Springfield in 2017.

Osborn is charged with two counts of second-degree murder and second-degree domestic assault.

Court records say his girlfriend, Valerie Williams, died of head trauma after an incident inside their apartment on March 1st, 2017. Williams was 16 weeks pregnant at the time of her death.

The trial began with an opening statement from the State. Derik Osborn’s attorney chose to waive his option to present an opening statement. Witnesses called by prosecutors include Osborn and William’s next door neighbor at the apartment complex. The man testified he and his wife had spoken with Williams once before, where Williams stated she was moving into the unit.

On the night of the incident, the neighbor told the court he heard the couple arguing, followed by a loud crash into a wall the two apartments share. He testified the crash was large enough to move items in his unit and sounded like someone had been thrown up against the shared wall.

Five other witnesses also took the stand Monday, all Springfield police officers or detectives who responded to the scene or conducted investigations following the incident. Police say the original 911 call was placed by Osborn and was listed as a possible drug overdose. The officers described Osborn as being in shock following Williams being taken to the hospital, and calm, unemotional, and evasive of specific questions officers asked him.

Evidence photos shown to the court depicted an apartment filled with unpacked boxes. Additional photos showed the couple’s bathroom, where a key chain with a small can of mace was laying in the bathtub, and droplets of what officers say was mace sprayed on the shower walls and toilet seat.

Based on early discussions in the trial, the defense is expected to claim Osborn and Williams were in an argument, when she fell in some way.

Additional photos taken by detectives showed photos of Williams while being treated at the hospital. The photos show abrasions on Williams’ neck, back, and knees.

The trial is expected to go into Tuesday after a full day of testimony on Monday. When finished, Judge Calvin Holden will decide on a verdict and sentencing.