How do you introduce evidence legally?

Flynn, arrested on purpose. Sentences delayed time and again and he is working with special counsel on other investigations and has met with them 19 times. https://www.npr.org/2018/12/05/673630919/flynn-met-with-doj-lawyers-19-times-muellers-team-says

Can't take anything at face value these days. Critical thinking re: Stone, Corsi, etc..