Vistavia Hills police said on their Facebook page that three people in St. Stephen’s Church were killed.
He explained that the assailant entered the church and shot three people, two of whom died.
He confirmed that he had arrested a suspect and that “the threat has been removed”.
The shooting took place in front of the church shortly after 6pm (11pm GMT) during a lunch, according to the site web of Santo Stefano.
The repeated mass shootings have sparked widespread outrage in the United States, where the majority of the population supports stricter gun laws, but opposition from many Republican lawmakers and voters has long been an obstacle to major changes.
On May 24, 21 people, including 19 children, were killed in a shooting in an elementary school in Yuvaldi, in Texas.
Since the beginning of the year, more than 20,000 people have been shot dead in the United States, according to the Gun Violence Archive, which also counts suicides in its data.