According to a probable cause statement filed Monday in 3rd District Court, Killpack questioned Wall about why he was inside the home, near 200 South and 1200 East.
"The intruder spoke to Killpack and provided Killpack with his personal contact information, including information about how to contact his family and his attorney," the document states.
As Killpack tried to verify the information, Wall attacked, stabbing Killpack first in the stomach and then the neck and head, police wrote.
Killpack managed to push the intruder away. A trail of Killpack's blood led from his home through an alley toward Douglas Street, a half of a block to the east. Killpack knocked on one home's door before walking two houses down and collapsing on a neighbor's front yard.
Police found Wall "covered in blood" and walking west on 200 South.
In an interview with police, Wall claimed he was invited into Killpack's home by a man he did not know, who had been sleeping on the balcony, according to a probable cause statement filed with the Salt Lake County jail after Wall's arrest last week.
Wall said "the old man" was mad at him because Wall had "messed with his pantings (sic)." He said "the old man" had tried to cut Wall's neck with a large knife and a small knife, and Wall said he fought with "the old man," the jail statement said.
Police said Wall had no injuries when they found him walking away from the crime scene. Detectives later found a large carving knife and a lock-blade-style knife inside Killpack's home.
Killpack, a former federal public defender who is now in private practice, was initially in critical condition, but police said the man's condition had improved late last week. Police said they were unable to provide an update on Killpack's condition Monday.
Wall remained at the Salt Lake County jail in lieu of $1 million bail.
A search of court records show Wall has a history of drug possession, theft and at least one break-in in Killpack's neighborhood.
Wall has spent significant time in drug treatment centers, court records show. In September 2005, he wrote to a judge asking to reduce a felony charge to a misdemeanor so he could pursue a career "working with adolescents and substance abuse."
In December 2010, Wall attempted to break into an enclosed back porch at a home one block south of Killpack's, according to court documents. Police later found $20,000 worth of stolen baseball cards and sports memorabilia along with syringes and spoons with burn marks on them at Wall's home.
Wall was sentenced to a year in jail for the crimes, but was facing a possible prison sentence after being convicted earlier this year on new retail theft charges, court documents show.
Court documents indicate Wall had begun using drugs again and was evicted by his landlord in April. In May, he was arrested charged with stealing pizza and a drink from a downtown grocery store.
Tribune reporter Brennan Smith contributed to this story.