In addition to participating in the intrusion, Schaffer is suspected of having attacked police officers with so-called bear spray - much like pepper spray with a longer range.
In total, he is suspected of six different crimes.
Stu Block, who has been the band's singer since 2011, announced his resignation on Facebook.
"There are times and events when you have to evaluate your life, work and future career," he writes, announcing that it is time to move on, heal and flourish.