Lots of details here....
http://www.wicourts.gov/sc/opinion/DisplayDocument.pdf?content=pdf&seqNo=161388
A few points...
The victim, Antony, was very drunk. He changed his story but eventually claimed that “he was beaten up by four people outside of a bar.”
The police followed a trail of blood next door where they found Matalonis.
“...Matalonis testified that he had been cleaning up blood when the officers arrived...”
“...The officers told Matalonis “that because there was blood in the house, [they] just wanted to make sure that no one else was injured.” Matalonis let the officers into the house....”
It appears there was a lot of blood, including “...there was a door with a deadbolt that had blood splatters on the door
itself...”
Well. That certainly adds a lot and supports an immediate search.