Which is more Important: Shutter Speed or Aperture

Mitch Tapper in an article in NATIA News titled, "Digital Photography for Law Enforcement - Which is more important: Shutter Speed or Aperture," concludes that in surveillance photography, shutter speed is the more important. He said, "I would have to say that in our line of work, I would favor the shutter speed because if you use a small aperture to gain depth of field and you have a lot of blur because you used a lower shutter speed, you will be worse off than having less depth of field and having more ability to eliminate the blur...If you do no want to shoot in manual mode, meaning that you are responsible for adjusting both the shutter speed and the aperture, then I would suggest shooting in Shutter Priority Mode, where you will pick the shutter speed and the camera will pick the corresponding aperture. If you pick too high a shutter speed, the camera will let you know that you are out of exposure range."