Mark Brennan is a Marine Corps veteran, serving as an Armorer with Marine Corps Security Force Regiment from 2009-2012. Mark later worked security for the Boston Red Sox, gaining valuable experience in professional sports and events. He also volunteered with a New England based non-profit organization assisting fellow veterans by helping find access to alternative therapies, tabling conventions, and general outreach. During his free time, Mark is also a professional photographer. His work has been recognized by being part of a permanent display/collection at a luxury Boston hotel.

At the beginning of the pandemic, Mark delivered canned goods to quarantined or housebound families while volunteering with Team Rubicon. He later transitioned into the cannabis industry as a regional security manager, overseeing 3 retail and 3 production/cultivation sites. Prior to joining home base, he became an explosive detection K9 handler with a 3^rd party security company.