SPG are Tanner Garza, Richard Ramirez, and Sean E. Matzus.
"Your First Time" and "Not Again!" were released in 2010 on Dead Audio Tapes. The project returned in 2012 with the H Series release, "Of Madness". A split tape (on H Series label) with the project, ...MASSACRE also came in '12.
Three years later, "Killed One by One" 3-tape set was released by Room 2A. "Blood Orgy" was also released in 2015 on Deathsex Electronics label.
In 2017, SPG has released their self-titled album on Room 2A.