SHADOWS FALL drummer Jason Bittner is filling in for ANTHRAX's Charlie Benante on the the first few weeks of the Rockstar Energy Drink Mayhem Festival, which kicked off yesterday (Saturday, June 30) in San Bernardino, California. Charlie is recovering from a minor hand injury.

Fan-filmed video footage of the San Bernardino concert can be seen below.

Bittner (pictured below) most recently filled in for Benante at two ANTHRAX shows in Argentina in February.

Benante and ANTHRAX bassist Frank Bello (who is Charlie's nephew) missed several shows on ANTHRAX's North American tour in order to spend time with Charlie's mother, who was terminally ill. On February 4, Benante informed fans via his official web site that his mother passed away.

Bittner previously joined ANTHRAX on stage on November 8, 2011 at Northern Lights in Clifton Park, New York to perform the ANTHRAX classic "Madhouse". He also filled in on drums for Benante for two ANTHRAX shows in January 2006 after Charlie was forced to leave the tour early to attend to his wife Sandra, who gave birth to the couple's first child, Mia Charley Benante.