Police Officer Mark Johnson, an Army reservist, will be missing from Sandy Springs’ streets for 400 days; he’ll be in Iraq for his second tour of duty.

Johnson, 36, participated in the 2003 invasion of Iraq while he was an officer with the Fulton County Police Department. He worked on a nuclear, biological and chemical reporting system with a unit that inspected Iraqi sites where missiles were shot down and areas contaminated by chemical warfare.

This time, the Woodstock resident will be with the 314th Civilian Affairs Company, based in Decatur, working to “win the hearts and minds” of Iraqis by helping construct schools, bridges, wells and anything else that might be needed.

“I’m actually very curious to see how the local people will accept us six years after the war,” Johnson said. “I guess you could also say I’m looking forward to it … just being able to help people who never had the chance to hope for anything better. I would say 99 percent of the people over there have always been oppressed.”

He is leaving behind his wife of 12 years, Michelle, and his 4-year-old son, Dean.

Dean “doesn’t really understand,” Johnson said, but he bought a laptop and a Web cam to keep in touch. He doesn’t know where he’ll be stationed but hopes for an area where an Internet infrastructure has been established instead of a “tent somewhere.”

“Back when we invaded, there was nothing. We used satellite phones to call home once a week,” he said. “I do have mixed feelings, but I do feel like the situation has gotten a lot better.”

Johnson flew to Fort Dix, N.J., for training with his unit April 11 and will deploy to Iraq in July.

— Gerhard Schneibel