A Kent County Circuit Court jury on Friday found Pedro Navarro, 27, guilty in the death of Aiyana Cisneros. Navarro is expected to be sentenced Sept. 4 to life in prison.
Navarro was arrested earlier this year. Police said he was the boyfriend of Samantha Winkler, who pleaded guilty in 2005 to second-degree murder in Aiyana's death.
Winkler was sentenced to up to 60 years in prison in the death of Aiyana, who had blunt force injuries to her chest and abdomen.
Defense attorney Paul McDonagh argued during the trial that Winkler harmed the child.
Police said that newly discovered witnesses and evidence led to the charge against Navarro.