There is no magic program, unless you can find the version all the police shows on TV use. For the rest of use about all you can do is play with sharpening, unsharp mask, contrast, etc.
Got it, doing that as we speak...
Just thought if I've got diff angles about those 2 theives, maybe the local police can find the potential ones...
And doing nothing except for waiting isn't really my style, especially when I caught them doing stealing thing under CCTV...
Is this the one that you're talking about?
As Curt points out, one is not working with high-resolution Images, from Video. There is also not a lot that can actually be done to "enhance" the Still Images from frame-grabs from Video. At best, you are probably working with 1920 x 1080 pixels, and there will be no embedded PPI/DPI. Most come over at 72 PPI, but that is really just to allow them to display on a computer monitor.
Along with Unsharp Mask, or Smart Sharpening, I usually work with Levels, or Curves, when trying to enhance Video Frames. I also often will Duplicate a Layer (Ctrl+J), and apply Shadow & Highlight (adjusting the Opacity of that Duplicate Layer, UP, or DOWN, as needed. In a few cases, I have also had improved results by doing a Duplicate Layer, then changing its Blend Mode to Multiply, and then adding Adjustments Layers and their corrections, to the "Multiplied" Layers. So much just depends on what you are starting with.
Back to the Frame Capture, depending on the program used, such as Premiere Pro, I would NOT Save that Frame Capture to JPEG, but go with BMP, or TIFF to start, then finally Save_As either TIFF, or PSD. As JPEG will compress an already poor Image, I do not want to introduce any degrading, at any step. Also, when you are playing the Video, deciding on which Frame(s) to Capture, scrub slowly, Frame by Frame, to make sure that you get the best one. I step back and forth, one Frame at a time, and study each one carefully. Sometimes, there will be one, or two Frames in a scene, that are much better, than others in that same scene.
Good luck, and do not be afraid to experiment with the various adjustments.