Did the UK crime rate go up after the '97 handgun ban? Yes.
Did the crime rate go up because of the handgun ban? No, unless you're asserting that a few thousand pistol shooting enthusiasts, most of whom already kept their weapons at their respective gun clubs & none of whom were permitted to carry a concealed weapon, were somehow between them holding back a crimewave in the years prior to the ban. Because if you're claiming a link between the ban and a rise in crime then that is what you're claiming.
Don't assume that the correlation that exists in the USA and that I am not seriously questioning holds true for the UK context. You can't compare the two, really.