CHICAGO -- Joseph Sneed knew right away something was wrong when he got home Wednesday night. The first thing he saw was not his beloved dog, Carmela, but a piece of luggage blocking the door, CBS Chicago reports.

"I opened the door and a piece of my luggage was at the door, behind the door, blocking the door. I knew that was completely abnormal," he said.

Joseph Sneed CBS Chicago

As he stepped inside he spotted his dog -- a red-nosed pit bull named Carmela -- lying in a pool of blood. Sneed immediately went back outside and called police. He feared whomever had broken in and killed his dog was still there, because the doors were still locked and there was no sign anyone had taken anything out of the home.

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"That's why I felt that somebody was still here," he said. "I have a security company. I'm a private detective. I carry a weapon. I do all of that. I teach concealed carry. I teach people who come to me not to go into these situations; even though it's your own home and even though your emotions would possibly overwhelm you to go. So I do what I actually teach. I don't just teach it and then do opposite. It made no sense for me to go in that house, even though I had a gun on me. ... It made no sense for me to go in there alone, not knowing the situation."

When officers arrived, they told Sneed they were going to search the home. A short time later, one of the officers asked him if he was sure no one was supposed to be in the house.

"I said, 'No. There's absolutely no one,' and he said, 'Well, we've got somebody,'" Sneed said.

Police found a 31-year-old man sleeping in Sneed's bed.

"He was a big guy. He was probably at least 6 feet tall, at least 250 pounds," Sneed said. "He was dressed in penny loafers, with some cutoff pants, shorts, and a summer-like shirt."

Police said the suspect had broken into the home through a second-floor window, and when he came across the dog, he stabbed Carmela multiple times.

Sneed said when police took the suspect out, he asked the man why he killed his dog.

"He just gives me this look, and just keeps walking, no expression," he said.

When Sneed finally went back inside, things kept getting stranger. Sneed's clothes were packed in the luggage that was left at the front door, empty plastic bags and clothes that weren't his were littered all over the house. Cans were strewn across his floor.

"He drank pop. He has pop cans all over the room," he said. "None of them, maybe one, was empty."

Sneed was at a loss for words when asked for his reaction.

"It's unbelievable, but I don't know if I should say what my reaction is," he said.

Police said charges were pending against the suspect Thursday.