I think it’s important to keep an open mind, and I’ve been thinking of alternate scenarios, ones in which BM isn’t involved. Here’s the one that I think is most probable:
I think the killer had familiarized himself with Suzanne’s routine, and had stalked her biking route on multiple occasions. On the day in question, he lurked just off the trail, crouching in the bushes, waiting for his opportunity to strike. As she rode by, he sprang out of nowhere, startling her. He knocked Suzanne off her bike, disorienting her. He quickly picked up the bike and flung it down the ravine as far as he could, so as to delay discovery of her disappearance. He then dragged Suzanne away, carefully removing any traces of his tracks left behind.
BTW, the perpetrator is a mountain lion in this scenario. Give me a break Barry.