After deliberating for just over 2½ hours, jurors found John Goff, 41, of nearby Stow, guilty of two counts of rape, two counts of sexual battery and one count of endangering children. He is to be sentenced Oct. 8 and could face up to 35 years in prison.
Goff frowned and looked at his family as the verdict was read. Summit County Common Pleas John Adams revoked Goff's bond and he was immediately handcuffed and led away.
Paternity tests showed that Goff fathered his stepdaughter's baby. The boy, born in 1999, is in foster care.
Goff's wife, 43-year-old Narda Goff, was convicted in March of helping him impregnate her daughter, Shenna Grimm, and was sentenced to three years in prison. She refused to testify against her husband.
Goff was convicted of breaking the rape laws that he campaigned for in the 1990s after a man accused of molesting the stepdaughter was acquitted because of a loophole.
The couple's campaign, which included sending letters to all 122 members of the state House and Senate, persuaded lawmakers to change the law in 1996 to include penetration with any object as a component to rape. Previously, only sexual intercourse was considered rape.
In closing statements Thursday, defense lawyer Tim Ivey argued that Goff did not commit a crime because his stepdaughter agreed to carry his child.
Ivey told jurors that she turned against Goff after the baby was born and her new boyfriend pressured her.
Prosecutors countered that Ohio's rape law is clear and that Goff raped his stepdaughter.
Grimm testified on Monday that she agreed to inseminate herself, but only because her stepfather, an auxiliary police officer and former Marine, put a gun to her head and threatened to kill her mother otherwise. She also said Goff twice used the syringe to inseminate her instead of letting her do it herself.
Assistant Summmit County Prosecutor Brian LoPrinzi said the circumstances of how Grimm, who will turn 20 on Friday, became pregnant are "not only immoral but illegal and disgusting." Grimm has been diagnosed with post traumatic stress disorder and depression and has attempted suicide.
"This is a case about rape. When you engage in sexual conduct with another person by force or threat of force, it is rape," LoPrinzi said.
"She knew he was violent and abusive. She didn't want to do it but she didn't even know it was wrong. They asked her, a girl with a fourth-grade education, to do the unthinkable without explaining any of the ramifications of having a child."