In September 2005 Threat Signal flew to Los Angeles to record their debut album, Under Reprisal, with producer Christian Olde Wolbers of the band Fear Factory. The band would combine the complexity of old school and European thrash metal music with de-tuned, technical syncopation, as well as melodic singing and musical passages. Threat Signal took influences from highly establish ed bands such as Soilwork, Fear Factory, Pantera, Meshuggah (Switzerland) and Devin Townsend.
As of late, the band has gone through a tremendous number of membership shifts leaving Jon Howard as the only remaining member from the original incarnation. One of the more notable members was Norman Killeen on drums until his departure in 2010 and subsequent death in 2016 after performing with Elevator 22 and Dyed in the Wool. As of May 2018, the line-up consisted of Jon Howard (vocals), Pat Kavanagh (bass), Travis Montgomery (guitars) and Matt Perrin (guitars). Most of the changes happening between 2005-2009 whereby their next recordings Vigilance (2009), Threat Signal (2011) and Disconnect (2017) would arrive.