There are different possibilities.
If you only want to apply the same crop to all your pictures simply use Irfanview
If you need "mostly" the same crop but want to fine-tune it, try JPEGCrops
For more involved detection, while may be better (one-click) tools available now, I have used
together with the Autotrim script
in the past.
Also, you can try to write a "crop" action for Photoshop or Gimp.