donnie brasco and a movie with a detective

Hey, i cant post links but is Donnie Brasco is full on youtube and in this movie cant find a scene where 2 guys i think take to a ride other guy to stab him, or probably a scene like this is in other mafia movie, like Boss of bosses?

And other movie with a detective who discover where horses sleep a clue about a criminal who is in high society and killed a women

Goodfellas. When Jimmy conway kills morrie.