this guy spamming my forum with threats

Please dnot delete this post because of bad words.. if theyre annoying, remove only the words please

yo.. ive got a visitor from god knows where in my forums.. he calls himself f**k_semikolon.. he visited my forum at my previous site too and he said i had deleted one of his post, which i hadnt done.. and because i had deleted that post, he should come and kill me and my family, my friends and sh*t.. he should also DoS atack my host..

now he talks about im in serious trouble because i dleted my previous site, where he had a post, im f**king my mum, smoking crack, stealing sh*t from other portals and use it in my own to earn money.. he also says he want to get a copy of the portal and give it away for free..

he also says that hes behind 17 or whateva proxies and blablabla..

is there anything at all i can do about this? (like contacting the police, my ISP, host whateva)

if you want to read what he has written, you can visit my forums at semikolon-asp.com.. i havnt deleted any of his posts..

this is not just something i say to get visitors.. im an honest guy, believe me.. but im really sick of this bastard..

this guy demands a public apology because i deleted one of his posts 30 minutes after he posted it...

oh my god.. what a sick bastard

blocking an IP address wouldnt help.. theres no problem getting a new one.. same with username..

i was just wondering, is there any chance of getting him prosecuted? this is serious threats!