OFFICER INJURED: What we know about the officer injured in Santa Fe High School shooting

SANTA FE, Texas (KTRK) -- At least 10 people have been killed and 13 others injured after a shooting at Santa Fe High School.

One of those victims included retired Houston Police Department officer and current Santa Fe ISD PD officer John Barnes.

HPD Officers Union President Joe Gamaldi confirmed to ABC News that Barnes was shot in the arm. He underwent surgery and remains in critical condition.

Barnes, 49, started his career with HPD in May 1995 and retired in January of this year, according to HPD Chief Art Acevedo.

"John is known for his tireless work in Houston Metro Internet Crimes Against Children task force," Acevedo tweeted.

Acevedo also visited Barnes' family Friday afternoon at UTMB Galveston.

"John is hanging in there and the family is very hopeful," Acevedo tweeted.