in memory of boris memtsov. >> he was a fierce and outspoken leader of vladimir putin. he was gunned down as he was walking home from dinner. >> i'm christi paul. >> i'm victor blackwell. huge crowds as we saw are taking to the streets in the heart of moscow. back to those live pictures here from the russian capitol. we've seen the number of people here increase steadily. they're paying tribute to boris nemtsov. he was shot and killed two days ago on a bridge 100 yards from the kremlin. he planned to lead an opposition rally. this is a march. they're moving through the streets, a march for him. they will actually pass by the spot where he was gunned down. it's now covered in flowers. >> we've seen a lot of flags and black ribbons, russian flags and