Thomas Hansen

Jury selection is under way for a retired Johnson County official accused of fatally shooting his companion in Riverside on May 1, 2011.

Thomas Lee Hansen, 72, of Riverside, is being tried on a first-degree murder charge in connection with the death of Sharon Gerot, 54.

Hansen is accused of shooting Gerot with a semi-automatic handgun while she was riding a lawn mower in their backyard, according to a criminal complaint. Investigators said the pair had been living together for years and had been arguing earlier that day, according to court records.

The couple was planning to go work at Yellowstone National Park, investigators reported.

Hansen retired as Johnson County’s emergency management coordinator in 2007. He worked for the Iowa City Fire Department before that.

Jury selection is expected to continue through the day, and opening statements are expected to begin late in the afternoon or on Tuesday.