Knox Lane, a San Francisco-based middle-market investment firm, completed the acquisition of a majority stake in Guardian Fire Protection Services, a fire protection services provider. Financial terms were not disclosed. "Guardian's highly resilient business model, culture, and strong foundation make it an excellent fit with the Knox Lane strategy, and we are grateful that Scott and the Guardian team have trusted us with their partnership. We look forward to helping to enable the next chapter of the Company's growth through our engagement, resources, and depth of experience," John Bailey, Knox Lane Managing Partner.