In this paper, we propose a multifunctional space-time modulated metasurface (STM-MTS) able to perform simultaneously a direction of arrival (DoA) estimation and radar cross section (RCS) manipulation in a single system. The metasurface consists of an alignment of unit-cells, whose scattering response can be dynamically controlled to be transparent (full transmissive unit-cell) or opaque (full reflective unit-cell), according to the amplitude of the modulating signal applied to the loading PIN diodes. The DoA estimation is performed behind the metasurface, i.e., in the transmission region, where multi-order harmonics of the incident field whose complex amplitudes are proportional to the DoA is transmitted. The multiple signal classification (MUSIC) algorithm is employed to estimate DoA. Simultaneously, the mono-/bi-static RCSs manipulation is performed in front of the metasurface, i.e. in the reflection region, where the reflected field is properly tailored by controlling the modulation scheme at unit-cell level. An X-band STM-MTS is fabricated to experimentally verify the feasibility of the proposed design. A DoA estimation errors are less than 2° in the incidence angular range of [-50°, +50°] is demonstrated, whereas mono-static and bi-static RCS manipulations of about 17dB and 36dB are achieved at operative frequency.Â