The trial for the Shores of Erie International Wine Festival resumed Tuesday in provincial offences court.

The trial is looking at whether the festival corporation violated its liquor licence by serving alcohol to a minor, who volunteered at the festival and died in a car crash in 2014.

Emily Bernauer was just 12 days shy of her 19th birthday when she was involved in a fatal crash that claimed her life.

Police have said there was alcohol and marijuana in her system at the time of the crash and an expert witness focused on that evidence in court Tuesday.

The corporation of the festival has pleaded not guilty for failing to inspect identification and for allowing a minor to drink at the 2014 event.

Bernauer of Amherstburg was a volunteer at the wine festival and was killed in a single-vehicle collision on her way home.

Police say the autopsy showed she had alcohol and marijuana in her system.

On Tuesday morning in court, forensic scientist and toxicologist Jean-Paul Palmentier testified as an expert witness.

He said alcohol was detected in Bernauer's system at the time of her death along with the active chemical in marijuana -- THC.

However, it was his expert opinion that the THC was likely consumed at least eight hours before the deadly crash and likely did not play a role in her impairment.

Palmentier also testified that cocaine, opioids and fentanyl were not detected in Bernauer's system.

Afterwards Renato Rota took the stand. He’s the owner of Amherstburg's Sobeys which had a food vendor booth at the same festival.

He is also the husband of festival board director Anne Rota.

Rota testified he had brought alcohol to the Sobeys booth as a token of appreciation for the volunteers and was not aware Bernauer was underage, until after her death.

He also claimed he had not seen Bernauer consuming any alcohol that night.

Tuesday afternoon festival chairperson Karen Gyorgy testified the main concern of security was that winery staff did not over serve, staff didn't think they needed to monitor food booths since staff there weren't serving alcohol.

Gyorgy also explained how there was a "zero tolerance" policy for festival volunteers drinking alcohol and that vendors were aware of it.