Determining an "IP" of an attacker means nothing about which ISP the attacker is using.
More often than not, the dialup account is stolen or created using fake info.

That IP may simply be one of many owned boxes usually never netting useful info.

Here in Colorado, unless you can prove significant damages, law enforcement
will tell you to pound sand and get in line as the frequency of similar events is
very high and not worth the manpower to pursue.