A mediator who worked with Adam Lanza’s parents during their divorce in 2009 says his mother said she didn’t like to leave him alone and that his parents went out of their way to accommodate him.

Lanza killed his mother before going to Sandy Hook Elementary School in Newtown, Conn., on Friday morning and killing 20 children and six adults before taking his own life.

Marriage therapist Paula Levy recalled Monday that during about 10 two-hour sessions, Nancy and Peter Lanza were respectful of each other and concerned about their son’s needs. She says the couple told her Adam Lanza had been diagnosed with Asperger’s syndrome, an autism-like disorder, and they spent considerable time talking about how to provide for his well-being.

Levy says the Lanzas agreed how to divide caretaking responsibilities and as a result said little about Adam’s problems.