Vote for the 40, with a caution.
Welcome to the forum, jalbuqurque,
Between any manufacturer's 9x17mm or .40 S&W, I would choose the 40. Between the Glock and the Taurus, I would buy two Taurus. If one proves less reliable than the other, send the one to be tuned up. And if either is not 100% reliable, keep tuning (preferably under warranty) so they are both 100%.
The .40 S&W will have greater stopping power than the .380/9x17mm, so that is what leads me to that chambering. If you shoot the smaller cartridge better than the other, that would reverse my suggestion. Your accuracy goes into the 100% reliability requirement as well. A proper hit with moderate stopping power is much better than a miss with superior stopping power, especially in police work, where misses are VERY much to be avoided.
I also would not spend any more time on that one tool (handgun) than I did on any other tool in my inventory. If my handcuffs were not 100% reliable, I would just as diligently ensure they work as designed, as well.
Your handgun will probably be the least used of all you pieces of equipment (hopefully, and the odds are that this is true).
Don't scrimp on anything you depend on. Probably the most important will be your shoes.
Whether you need good traction, good arch support, good accuracy or good stopping power, you will need it, and the time you need it is no time to find out you or your gear comes up wanting.
Lost Sheep