That's not the full image. The full image (https://twitter.com/MerseyPolice/status/1395783747115618306) has a lot of detail in the palm area - enough to get a match I'd assume, if they have his full palm print on file.

Even if it's not a super high probability match, it could have been enough to give them a name and find more evidence.

I don't buy that they'd make up the story _and then tweet proudly about it_, especially when the image they posted is so easy to be sceptical about because of the blur.