No criminal charges will be filed against a fired school resource deputy who had a sexual relationship with a former Central Valley High School student.

Deputy Prosecuting Attorney Kelly Fitzgerald said the investigation conducted by the Washington State Patrol shows that the relationship between Spokane County Sheriff’s Office Deputy Mark “Cole” Speer and the girl did not turn sexual until after the 18-year-old had graduated from Central Valley.

“In the State of Washington, 16 is the age of consent,” she said.

Fitzgerald said she reviewed WSP interviews with witnesses, including Speer and the girl, and text messages the two sent to each other. Speer had worked as a resource officer at the high school since 2011.

Speer was fired last month after an internal Sheriff’s Office investigation. He filed a grievance appealing his termination through the Deputy Sheriff’s Association but the union’s board declined to take it forward, said DSA president Deputy Kevin Richey.

“They just didn’t feel that we’d be able to prevail,” Richey said.