You can buy individual episodes or the full season digitally. Apple TV Store: Available for purchase and download.
Offers all episodes of Season 1 with various subscription plans, including ad-supported and no-ads options. the mentalist season 1 link
If you are looking for a direct link to start your binge-watch, the following services offer the complete first season: You can buy individual episodes or the full season digitally
The first season of The Mentalist debuted in 2008, introducing audiences to Patrick Jane (played by Simon Baker), a former "psychic" medium who turned his life around after a serial killer known as Red John murdered his family. Using his expert powers of observation and psychological manipulation, Jane joins the California Bureau of Investigation (CBI) as a consultant to solve complex crimes while hunting for his family's killer. If you are looking for a direct link