Reice Tisdale, Jr., a police detective, was off-duty Friday when he learned about the shooting at Santa Fe High School.

Tisdale's mother, Cynthia Tisdale, worked a substitute teacher at Santa Fe high, and his daughter also went there, according to his statement, which was read on his behalf at a news conference on Monday.

Tisdale, who lives only 10 minutes from the school, immediately gathered his gear and headed to the campus to help.

"Once the scene was somewhat secure, I was contacted by my father who could not reach my mom," he said. "I knew that two female teachers had been killed along with several students."

"Not long thereafter, I determined that one of the teachers was probably my mother. It was very hard to go from assisting others to be horribly affected by this tragic event."

Tisdale said his mother "enjoyed helping others so much" that she decided to work as a substitute teacher for children with special needs.

"She worked at the school not out of necessity but for the love of teaching and helping others," he said. "To know my mom was to know a person who lived to help those in need. We loved our mother very much. Grammy you will be missed."