A 69-year-old Ocala man has been arrested in the deaths of his two roommates, which police say followed an argument over ice cream.

The Ocala Police Department arrested Mark Robinson on Wednesday night on suspicion of second-degree murder. Two men had been shot at his home on SE 8th Street. Police said one person was found dead inside the house. A second person was found shot outside and was taken to a hospital, where that person later died.

On Thursday, police released further details about the investigation. According to the department, officers first went to the home on Wednesday morning after the three roommates argued over someone allegedly eating another person's ice cream. The two roommates then left the house and went for a walk.

Robinson told police he armed himself with a shotgun while they were gone because he feared something bad was going to happen. When the roommates came back, he said, another argument broke out, and one of them allegedly "charged" at him while holding a knife, investigators said.

Police said the second roommate ran out of the house and into the front yard, where Robinson shot him in the back. Robinson then surrendered to officers and admitted to shooting both men, according to police.

Investigators described the household as a "dysfunctional living arrangement" and characterized Robinson as an "angry old man" with alleged alcohol issues. Police said they had been called to the home three times this year. Those earlier calls involved disturbances between Robinson and his roommates or his neighbors.

Robinson has been charged with one count of second-degree murder in connection with the shooting of the roommate in the front yard. He has claimed self-defense in the death of the roommate he said was armed with a knife inside the home. Detectives are still investigating that shooting.

Ocala police said additional charges are possible as the investigation continues. The department shared its information in a release and at a news conference.