Lt. Bill Walsh, a 27-year veteran with an international reputation as an expert in his field, was honored Wednesday at a reception attended by about 200 people at the Jack Evans Police Headquarters.

"It's been good for the city of Dallas and law enforcement across the world that Bill got involved investigating crimes against children," said Police Chief David Kunkle, who emceed the ceremony.

Lt. Walsh, 52, founded the department's child-exploitation squad and started an annual crimes-against-children seminar in Dallas. He also was instrumental in creating the Dallas Children's Advocacy Center, one of the first such facilities in the state.

He helped start the Dallas County Child Death Review Team, which also was among the first in the state. And he secured funding to start a task force to investigate computer crimes against children.

Operation Avalanche, which started in 1999, and Operation Site Key, which began in 2001, two of the largest Internet child-porn investigations, were led by his investigators. Each led to the arrest of hundreds of child-porn suspects around the world.

"Bill has changed the landscape on the police response to child abuse and neglect," said Pete Banks of the National Center for Missing & Exploited Children. "Dallas police has become the standard of excellence."

Lt. Walsh will continue as a reserve officer and work with the child advocacy programs.