An argument about religion in Tennessee escalated when a woman struck a man on the back of his head, prompting him to retaliate by shooting her with a shotgun, according to authorities.

Calvin Johnson, Sr., aged 69, faces charges of first-degree murder following the fatal shooting of a woman tentatively identified as 45-year-old Tamara Perkins, according to an arrest affidavit examined by Law&Crime.

The violence unfolded on Tuesday.

The affidavit reveals that Johnson, Perkins, and another individual were consuming alcohol at a residence on the 3100 block of Morningside Street in Memphis. During their time there, a dispute arose as Perkins and Johnson engaged in an argument about religion, as noted by the police and the third party present.

The eyewitness reported to police that Perkins poured a drink over Johnson’s head and then slapped him on the back of the head, as documented in the affidavit. The tension heightened, but the conflict did not end there.

Johnson allegedly “retreated briefly to his bedroom and returned armed with a shotgun, at which point, without speaking and seemingly without provocation, he shot Perkins,” the affidavit states. Perkins was unarmed, and no threats were exchanged, the witness informed the police.

A Memphis police officer arrived at the home to find Perkins unresponsive “with a gunshot wound to the upper left abdomen lying next to a double barrel shotgun inside the residence,” the affidavit states. Johnson was observed “on top of the victim,” and when the officer asked him what happened, he is said to have replied, “I shot her,” police wrote.

Perkins was brought to a nearby hospital where she died. Johnson was arrested.

When homicide detectives interviewed Johnson back at their bureau, he allegedly uttered several phrases unprompted, such as “I killed her” and “I’m in trouble, ain’t I?”

The suspect is also said to have uttered, “I messed up, didn’t I?” and when told of his Miranda rights, refused to answer questions, allegedly asserting instead, “She came at me and she a big woman.”

Court records show Johnson has a bail hearing on Monday and then must report to court again on Thursday.