Trula Ann Godwin was born in 1940 on a farm near Okmulgee, Oklahoma, to Marguerite Marrs Godwin and Lloyd Godwin, a sharecropper. She moved with her family to Davenport, Iowa, after graduating from Okmulgee High School when her stepfather, Willard Smith, decided to attend Palmer College.

Godwin married Darrell Tanner and the couple had five children. In 1971, when her last child was five months old, she was raped in her home. Because she felt that the police's handling of her case was inadequate, Trula Tanner joined the Davenport Police Department in 1973, hoping to improve the way rape investigations were conducted. She patrolled the inner cities where she became well-known and much beloved, and became a sex crime specialist.

She served an annual Thanksgiving feast at a downtown bar, and helped distribute clothing and supplies to those in need. Godwin never went up for a promotion because she preferred to stay on patrol and work the inner city beat. She also became a friend of Governor Terry Branstad. Godwin, who resumed using her maiden name after her divorce in the mid-1970s, retired from the Davenport Police Department in 1998 and died of cancer in 2002.