A 50-year-old psychologist and community college instructor is being held in the Genesee County Jail on charges of a double stabbing in Flint.
William Harshman faces charges of assault with intent to murder and first-degree home invasion in a Christmas Eve attack that wounded a woman and a teenager.
Authorities say he went after Lisa Heintz and 17-year-old Edward Lapine at the woman's home.
The Flint Journal reports Lapine was helping Heintz's family pack boxes for a move.
Detective Matt Harburn told a judge Wednesday that Harshman stabbed Lapine in the back with a kitchen knife before going after Heintz, who suffered a broken arm and cuts on her chest.
The Heintz family has been in the mortgage business and reportedly had dealings with Harshman.