Add video change start to 00.02.00.000 leave end as is
Click CUT
Add a to end of description (its easier to identify)
Then Save
Then click Join at top
Add new file (******** a) add 2nd video
Click Join (new file is called all joined or something)
HTH
Also, I am not good at editing video's but I know of a free app called Freemake Video Converter that will allow basis editing and excellent format conversion. This would probably do what you want. When I convert I save to MP4 format for size and quality, at same resolution as source. Hope this helps mate. Only download it from a reliable trusted source.
But good job catching these pricks in the act.. hopefully the police will catch up with them.
Let's say it's not the fist time seeing you 07701340830 xo