The voice reporting here
https://m.youtube.com/watch?v=P_N2ezvK-Ng
said it was the Secret Service and that they have shot a woman dead. I saw a woman on the floor, blood all over neck area, looked like cops handcuffing her then flipping her over then providing assistance, while a cop with a ... M16? type weapon provided cover standing behind them. There was also the sound of more indoor handgun fire before the video cut out for me temp
Reminds me of the Boston Massacre