Downloads for current version can be found here.

# apt-get update
# apt-get install python-pyinotify
# cd ~ && mkdir f2btmp && cd f2btmp
# wget https://github.com/fail2ban/fail2ban/archive/0.9.4.tar.gz
# tar -xzf 0.9.4.tar.gz
# cd fail2ban-0.9.4
# python setup.py install
# cp files/debian-initd /etc/init.d/fail2ban
# cd ~
# rm -R f2btmp/
# update-rc.d fail2ban defaults
# /etc/init.d/fail2ban start