I love a good creepy mystery. Thanks.

Two thoughts - first, the famous shot of the backyard looks to me simply like someone picked up the camcorder (it would have been a VHS tape recorder or something similar back then) and, forgetting or not knowing that the Tara tape was in it or mistakenly hitting the "record" button, tested the camera and the zoom function by pointing it outside a window.

Second, I found a grave for John Bergeron that matches the year and place you found: https://www.findagrave.com/memorial/63520325/john-louis-bergeron