Well... NCH has Video Surveillance software that advertises...
Find and play surveillance recordings ordered by camera, date, duration and motion detected
Ocularis PS is a comprehensive surveillance system solution that includes video analytics that can be set to review video for movement... but would probably be quite expensive for just this one task.
Gotcha is a small program that can be used to view live or recorded video and includes a motion detection feature.
ContaCam is a free solution that offers the ability to review existing movies and motion detection, but I don't know if you can combine them both. But, as it is a free option, it's definitely worth looking at.
Otherwise, most solutions offer motion detection as a feature of what is recorded by the software, as opposed to monitoring an existing recording.
Then again, you could always just open the raw video in an editor, and play it at a high speed, looking for movement. When you see it, you pause, back up a little, and tag those sections.