Stephen Simpson is being held in custody in Michigan and is expected to be charged with attempted murder and home invasion after he purportedly knifed his victim while his estranged wife was in the apartment on Monday (18.08.14), US news channel 'WWMT' reports.
Neighbour Torrey Hunt says he found the victim bleeding and begging for help when he opened his door at 3am.
He explained: "He said someone knocked on the door, he thought he was knocking on the door for somebody, and he started getting stabbed up.
"I open the door and see blood everywhere. He was stabbed in his chin and his chest, he had puncture wounds in his chest and his arms and stuff."
Simpson, who is currently on probation, has a history of domestic violence and it is not known whether he has a close relationship with Jennifer.
The incident is likely to bring back terrible memories for the singer - who has the same father as the 45 year old - after her mother, brother and nephew were murdered in 2008.
William Belfour, the estranged husband of her sister Julia, was convicted for the crime and handed three life sentences.