What famous movie opens with a scene of a man sitting on a park bench in a scenic part Washington DC, perhaps near a monument? He phones his wife and kids on his cell phone, then hangs up and pulls a revolver out of a brown paper lunchbag, and then shoots himself in the head... famous movie, big name stars... what movie is this, please?

I figured it out myself. "The Net" (1995), with Sandra Bullock.