Hundreds mourned a slain Dallas police officer during a candlelight vigil outside police headquarters Thursday night.
"What I most know Norm for is the way he loved his wife, Regina," police Chief David Kunkle said.
The highly decorated officer was assigned to the department's elite gang unit. He was shot and killed Tuesday night while trying to serve a felony warrant at an Oak Cliff apartment complex.
"You have ex-gang members out here wearing "rest in peace" shirts in his behalf," said former gang member Lamont Lewis. "I don't know what other cop in the city of Dallas they would do that for."
Smith was acting on a tip from an informant at the end of a 12-hour workday when he was shot.
"We thought of Norm as a general leader, invincible," said. "We never thought this could happen."
Family and co-workers remembered Smith as tireless crime fighter, a devoted father and a loving husband.
Kunkle told crowd of mourners that Regina Smith was adamant that her husband never show her affection when they were both in uniform.
"For reasons Regina will never know, other than a miracle, she kissed Norm that day in our building," he said. "It was the last time she ever saw Norm."
Smith's fellow officers said they will continue his work, knowing a guardian angel will be watching over them.
An honor guard raised a Flag of Honor to half-staff outside Dallas police headquarters Thursday in memory of Smith. The flag flew over the Texas capitol on Sept. 11 and now travels the country to honor fallen police and firefighters.
The tribute to Smith on his squad car outside police headquarters continued to grow Thursday. The vehicle will be parked outside through Friday.
Smith was the first police officer killed in the line of duty this year.
Funeral services will be held at 11 a.m. Friday at the Potter's House in Dallas. The memorial will be streamed live on NBCDFW.com.