Bruce Funk, who has worked in the cellular technology field for 46 years, told an Edmonton court he was asked to pinpoint cell service in areas west of Edmonton as well as the cell towers used to activate calls.

During the trial’s opening statement, the Crown alleged Vader used the McCanns’ cellphone to make calls to his ex-girlfriend Amber Williams.

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Vader, 44, has pleaded not guilty to two counts of first-degree murder in the deaths of Lyle and Marie McCann from St. Albert.

On Sept. 8, 2011, Funk drove out to the Wabamun area to see what cellphone tower would pick up a sending or receiving call.

“I can never tell you that a cellphone was at a certain address,” Funk testified, adding he could only tell if a cellphone was in a “general” area.

The Crown alleges seven calls were made in a span of less than five minutes, followed by two text messages.

Funk told court his cellphone tests also included the Gainford Trading Post along Highway 16.

He said he also went to the Nojack rest stop, Nojack campground, Peers weigh scale, Edson rest stop, and the Minnow Lake campground where the McCanns’ burned out motorhome was discovered.

The Crown had wanted Funk to testify as an expert witness so he could provide his opinions. However, in a ruling, Justice Denny Thomas limited the testimony to factual evidence from the test results.

The McCanns, who were in their late 70s, were last seen fuelling up their motorhome near Edmonton on July 3, 2010.

Two days later, the motorhome was found on fire about 200 kilometres west of the city.

Their bodies have never been found.

The McCanns had been on their way to a family camping trip in British Columbia.