Die Hard holds up really well as a film, Lethal Weapon... not so much. And not only because of Mel Gibson's mullet. There's a limit to how much suspension of disbelief you can take. Shouldn't cops behave like... oh, I dunno, cops? And how stupid does Shane Black think the viewer is? We see Gibson putting a gun in his mouth. And also holding a photo of his dead girlfriend to make it more clear. I believe he also says -I miss you, babe, or something, for the people in the back row. Then we see him behave suicidally at work. Three times? Sure, why not. And then have the psychiatrist explain to the captain of the police station that Gibson is suicidal, just in case we missed the clues.