David Ridgeon has always been drawn to cold cases.

But on the latest season of his podcast, someone knows something.

Rijin doesn't just investigate a cold case.

He becomes a part of it.

They can't get him to talk, but it's the work that gets him to talk.

It's the documentary.

I'm Kathleen Goldthard, and this week on Crime Story, I talk to David Ridgin about the Christine

Heron case. Find Crime Story wherever you get your podcasts.

This is a CBC podcast. I'm at another river,

this one, flowing through a southwestern Ontario town, on a clear but darkening springtime evening.

I recorded these nature sounds well over a decade ago for a TV documentary using the

same microphone I now use for the podcast.

This thing always seems to be standing between me and the unknown, somehow oddly comforting.

I was crouching at the riverside here in a park in Hanover, Ontario.

This is the Sogene River, which the mouth of the Sogene

actually empties out into Lake Huron.

It's about 60 kilometers downstream, I think.

The river's flowing clear, but there's lots of debris kind of pushed against the shoreline. There's obviously a pretty high floodplain here.

There's an old gazebo, a swing set. There's an old gate.

I remember focusing on the sounds these things made here.

Chains on a swing, muddy logs at the high watermark,

brushy grasses along the path, and that metal gate.

...