Few details emerged about the man whose Cudahy duplex apartment was searched by police hours after the shooting in Milwaukee's Oak Creek suburb.
He was described as white, single, in his 40s and an Army veteran.
"That description came in part from Kurt Weins, who lives in the 3700 block of E Holmes Avenue in Cudahy. He said he rented the property to a man he believed to be from Chicago with no record of violence in Wisconsin," Milwaukee-Wisconsin Journal Sentinel reported.
Authorities did not tell Weins whether his tenant was the shooting suspect, but the description matches that of the man that sources said was the shooter, the report said.
ABC News, citing unnamed sources, said it was told the shootings were the work of a "white supremacist" or "skinhead".
Weins said he ran a thorough check on the man, whom he would not name because police told him not to disclose the name.
"I had him checked out and he definitely checked out," Weins said. The man appeared to be something of a loner, he said.
Tattoos on the body of the slain gunman and certain biographical details led the FBI to treat the attack at a Milwaukee-area temple as an act of domestic terrorism, Los Angeles Times said quoting sources.
Eyewitness have said that the shooter had a "9/11 tattoo" on his arm.