A Lusk man will be tried next week on three felony charges resulting from the deaths of a woman and her infant son in an accident west of Casper in August 2017, Natrona County District Attorney Dan Itzen said Monday.

Alexander Sebastian Richardson is charged with two counts of aggravated vehicular homicide and one count of aggravated assault. He could face up to 50 years in prison if convicted on all charges.

The trial is expected to last for about five days, Itzen said.

He pleaded not guilty during his arraignment in August.

The case started on the afternoon of August 23, 2017, when Richardson was driving on Wyoming Highway 220 to his home in Lusk, according to a report from the Wyoming Highway Patrol.

About 1:20 p.m., Richardson's Ford F-250 drifted across the center line into the westbound lane, where it collided head-on with a Ford Explorer carrying 46-year-old Soon Young Lee, Bong Jun Seo and 3-year-old Jaehyeok Seo.

According to an affidavit filed in the case, witnesses said that Lee died immediately.

The infant had a pulse when a Carbon County nurse stopped at the scene and rendered aid, but the child's pulse was lost within a few minutes and the nurse began to perform cardiopulmonary resuscitation.

The nurse told investigators that the baby had a head wound and possible broken neck. She continued CPR until Life Flight arrived, but the child did not survive.

Seo was injured, but survived.

After Richardson's arraignment in August, his attorney Don Fuller told K2 Radio News that he has hired the Littleton, Colo.-based OEC Forensics to perform an independent reconstruction of the crash.

Earlier this month, District Court Judge Kerri Johnson dismissed a request by the prosecution to admit into evidence a previous traffic incident in which Richardson was pulled over by law enforcement. He was having a reaction to fluctuating blood sugar levels.

Johnson ruled that the circumstances with this incident were not related to the current charges and mentioning it could prejudice the jury.