takes his own life on a subway platform as police close in. hours later police announce officers wenjian liu and rafael ramos died, murdered for the uniform that they wore. based on social media posts authorities believe brinsley was bent on revenge, angry over police killings of african-american men in new york and missouri. >> two of new york's finest were shot and killed with no warning, no provocation. they were, quite simply, assassinated. >> reporter: investigators say a review of brinsley's cell phone contained video they believe he shot in manhattan earlier this month at a protest over the deaths of eric garner and michael brown. brinsley's string of violence began early saturday morning about 200 miles away. police say he gained entrance to his ex-girlfriend's apartment somehow through the lobby and knocked on her door. she told police he threatened to shoot himself. after the woman talks him out of it, brinsley shoots and wounds