GPS technology the focus on Day 5 of second-degree murder trial of Erick Buhr

Testimony continued Monday at the trial of Erick Buhr, who has pleaded not guilty to the second-degree murder of his grandmother, Viola Erb.

At the time of her death, in September 2022, Buhr was serving a conditional sentence and wearing an ankle bracelet. That device was collecting data on his location once every minute.

The Crown showed maps, as well as raw data, of Buhr’s locations in court. That information was gathered from his ankle bracelet between 11 a.m. and 2 p.m. on the day of Erb’s death.

Stephen Tan, the director of operations for the company that operates the compliance monitoring program, took the stand Monday.

He said the system requires communication with five to 21 satellites to get a location. When a bracelet is outside, there are fewer obstructions in the way and it can typically access more satellites. He testified that, when the person wearing the device is inside a building, like a house, they “generally expect to see nine or 10 satellites.” Tan added that the technology uses civilian GPS which, as a starting point, has a margin of error of 50 feet.

He noted that the data collected between 12:50 p.m. and 12:59 p.m. on the day Erb died showed two points that appeared to be far from the Sandhills Road home. But, given that nine satellites accessed the location, Tan suggested it was much more consistent with the bracelet being indoors.

Earlier in the trial, Sgt. Andrew Kroetsch said Buhr took him to a wooded area behind the home where, he claimed, he had been sitting when his grandmother was attacked.

During a lengthy cross-examination, Buhr’s lawyer Bruce Ritter raised questions about the accuracy of the ankle bracelet data.

Tan testified that it gives them a idea of the location but, in this case, not two or three football fields away.

“Seems to me, something’s either accurate or it’s not,” Ritter stated.

The trial is set to continue on Tuesday.

History of the case

Erb was found dead in her home, just outside of Baden, on Sept. 24, 2022.

According to her obituary, the 88-year-old “passed away suddenly and unexpectedly.”

Waterloo Regional Police and the Office of the Chief Coroner later determined her death was suspicious, however they did not say how Erb died or why it was believed to be a homicide.

Buhr was charged with second-degree murder five days after Erb’s death.

On Friday, the forensic pathologist who conducted the victim’s autopsy testified at Buhr’s trial.

Dr. Linda Kocovski explained that Erb died from “external neck compression and blunt force head trauma.”

She said she found numerous injuries on Erb’s head, including lacerations on her forehead, under her eyes, on her nose, lips and inside of her mouth. Erb also had fractures to her nose, the bones around her eyes, cheekbones and upper and lower jaw bones, as well as two black eyes.

In cross-examination, Ritter noted Erb was on blood thinners and asked how that would impact bruising. Kocovski confirmed that bruises may be larger on individuals who take blood thinners.