Chase HQ 2 (Special Criminal Investigations) is now likely to be an Amstrad urban legend.
Originally it was thought it was never released and never finished, however it has since been reviewed in Retro Gamer, and there is believed to only be 1 copy in existance.
There has been lots of talk about this cartridge and even attempts to contact the author for transfer. But as of this date, nothing has come of it.
So at this time nobody believes it exists.