This dissertation is structured in four chapters. First, the reader is introduced to current detection methods for astrophysical black holes at different scales. The following three chapters correspond to different research projects regarding black hole detection. The second chapter presents the kinematic detection of a supermassive black hole at the center of the dwarf spherical galaxy Leo I. Chapter three presents a novel idea for the detection of supermassive black hole binaries using the effect their gravitational waves produce on lower frequency gravitational waves in our vicinity. Finally, chapter four describes the spectroscopic follow-up of LIGO-Virgo-Kagra gravitational wave sources conducted using the Hobby Eberly Telescope at McDonald Observatory.