Southfield Capital-backed Protos Security, a tech-enabled managed security services provider, has acquired Security Resources, a leading US-based managed security services and direct guard solutions provider. Financial terms were not disclosed. “Over the last 20+ years, SRI has blossomed into one of the leading names in the security services space and they have built a highly respected business with a great client roster. We believe that combining SRI with Protos’ industry leading technology will enable us to deepen client relationships and provide a broader array of comprehensive security and loss prevention solutions,” Andy Cook, Southfield Capital Partner.