P.I.s, or Private Investigators, are professionals who specialize in gathering information and evidence for legal or personal matters. TECS stands for 'Technical Surveillance Countermeasures, ' which is a type of investigation that involves the use of specialized equipment to detect and prevent electronic eavesdropping. LIBRA stands for 'Licensed Investigations Business Regulatory Act, ' which is a set of laws that govern the practice of private investigation in some states.