In one, after the closing shot with Richard Gere walking into camera, it cuts to Ethan Hawke's partner going to inform Lili Taylor of his death; unsurprisingly, she goes into meltdown. Then there's a pan across the city to a rooftop, and a newspaper with Hawke's, Gere's and Cheadle's faces on it saying 'Brooklyn's Finest'; and a subtitle saying three different officers, one wild night. Someone then lights this and puts it on fire, respectfully; we see its Wesley Snipes, his character still alive, bandaged, wearing a hat and carrying a case. He's leaving, with one last trip to that rooftop to pay his respects to his dead friend who tried to save him:- even if he was a cop. In the other, after the Gere into camera shot it cuts to him on a lake in Conneticut or wherever (sorry about the spelling), lovely day, lovely scene, him smiling and seeming at peace; then he picks up his .38 Special, puts it in his mouth and blows his brains out. Personally like the first alt-ending, not the second; over-the-top dark even for this film.
I watched the alternate endings on the Blu Ray and I also didn't the suicide ending but I wish Fuqua had stayed with the original ending with Sal's widow being comforted and Caz paying a tribute to Tango on the rooftop. Those scenes were powerful.