MANITOWOC - According to newly unsealed documents, Steven Avery's nephew told authorities his uncle wanted to kill Teresa Halbach because he couldn't adjust to life outside prison, and he wanted to be back behind bars. That's the message in one of the documents unsealed in advance of today's motions hearing in Manitowoc County Circuit Court for Avery's case. Avery and his 16-year-old nephew Brendan Dassey are charged with raping and murdering the 25-year-old photographer and then burning up her body last Halloween. A motion by Special Prosecutor Ken Kratz argues that Avery's jury should not be told about the 18 years Avery spent in prison for rape before DNA evidence exonerated him, and he was released in 2003. But defense lawyer Dean Strang contended evidence about Avery's time in prison cannot be ruled out if prosecutors require Dassey to testify about something else -- Dassey's alleged statements that Avery was unable to adjust and killed Halbach, so he could go back to prison.