Police chief says Dallas shooting attack on officers was "well planned"

DALLAS - The Thursday night sniper attack on Dallas police officers during a protest over police-involved shootings was "well planned," Police Chief David Brown said during a midday citywide prayer service here.

"We won’t rest until we bring everyone involved to justice," he said, to a roar of applause.

UPDATE: Crowds line up to hug police officers in Dallas 

Hundreds of people packed Thanks-Giving Square Park for the service, which included prayers, music, tears and tributes.

Brown spoke only briefly, saying he had to leave promptly to return to the investigation, but began his remarks by saying police work is a job where you seldom hear the words "Thank you."

The crowd responded with a deafening THANK YOU!