. >> it appears the shooter is going to be david o'neill brown jr. >> chief brown's only son and hise was himself killed after he gunned down two other people. one of them a police officer. >> i remember closing my son's casket in the church. i remember sitting at the burial site and everything else is a blur. >> reporter: the 30-year police veteran has endured the violence death of his brother and police partner. while sometimes abrasive, he is known for his kindness, often putting pictures showing his dedication to the people of dallas. >> we are not going to let a coward who would ambush police officers change our democracy. >> reporter: tonight, when his city needs it the most, he is a strong, steady voice of passion and concern specially for his fellow officers. >> all i know is that this must stop. this divisiveness between our police and our citizens. >> chief brown has dedicated his whole life to one job. >> i have never been more proud of a police officer and being part of this great, noble profession. >> reporter: a department that has been put to its greatest tests with it

david brown. >> less than two months after she was sworn in as chief six years ago, he was tested in both professional and personal way. >> i appears the shooter is going to be david o'neilrown jr. >> chief brown's only son was killed after he gunned down two other people. one of them was a police officer. >> i remember sitting at the burial site and everything else is a blur. >> the 30 years police veteran endured the violent death of his brother and his police partner. he's always known for his kindness and often posting pictures on social media showing his dedication to the people of dallas. >> we are not going to let coward who would ambush police officers and change our democracy. tonight what his city needs the most, he's a strong steady voice of compassion and concerns especially for his fellow officers. >> all i know is that this must stop. this decisiveness. >> chief brown has dedicated his whole life to one job. >> i can tell you, i have never been more proud o f our police officers and be apart of this great noble profession. >> a department that's put to its greatest tests with his chief commanding the way. >> nbc news. >> reporter: joining me now casey tomas

. >> it appears the shooter is going to be david o'neil brown junior. >> chief brown's only son and his name sake was himself kil d after he gunned down two other people, one of them a police officer. >> i remember closing my son's casket in a church and i remember sitting at the burial site and everything else is a blur. >> reporter: he has also endured the violent deaths of his brother and former police partner. he's known for his kindness, often posting pictures on social media showing his dedication to the people of dallas. >> we are not going to let a coward who would ambush police officers change our democracy. >> reporter: and tonight when his city needs it the most, he's a strong, steady voice of come pags acome -- compassion and concern for his fellow officers. >> i know this must stop. >> reporter: chief brown has dedicated his whole life to one job. >> i could tell you i have never been more proud of a police officer and being a part of this great noble profession. >> reporter: a department that has been put to its greatest test with its chief commanding the way. >> up next,

. >> it appears the shooter is going to be david o'neill brown jr. >> reporter: chief brown's only son and his namesake was himself killed after he gunned down two other people, one of them a police officer. >> i remember closing my son's casket at the church. i remember sitting at the burial site, and everything else is a blur. >> reporter: the 30-year police veteran has also endured the violent deaths of his brother and his former police partner. while sometimes abrasive, he's also known for his kindness, often posting pictures the on social media showing his dedication to the people of dallas. >> we are not going to let a coward that would ambush police officers change our democracy. >> reporter: and tonight, when his city needs it the most, he's a strong, steady voice of compassion and concern especially for his fellow officers. >> all i know is this must stop, this divisiveness between our police and our citizens. >> reporter: chief brown has dedicated his whole life to one job. >> i have never been more proud of being a police officer and part of this noble profession. >> reporte