This scenario would fit the 'forgiveness' comment by JAR, so SOON after the murder.
From Steve Thomas book: page 57...
We asked him (JAR) to put his thoughts on paper, and he wrote a document that brimmed with feelings about his little stepsister being murdered, giving us a glimpse into his world. He caught out attention immediately by writing, "I think it was someone that had intimate knowledge of my family and how we lived day to day. Why would they leave the ransom note on the back staircase instead of the front?"
Good question, I thought. How would a stranger know which stairway Patsy Ramsey would come down that morning?
He ridiculed the idea of a small foreign faction being involved, was certain the crime had nothing to do with his father's company, and questioned why a ransom note was left at all. "Why did they ask for $118,000? I could pay that amount," he wrote. Someone was envious of their wealth and thought of the Ramseys as "rich bastards", he said.
John Andrew told us that whoever did this was probably uneducated, were amateurs at kidnapping, and had seen the movie Ransom, in which the family of Mel Gibson's character was a "spitting image" of his own. He did not believe anyone came in through the broken basement window. They had a key, he surmised.
In one comment, he described his stepmother as "flashy" and guessed that the killer might be someone close to her.
John Andrew also buttressed the comments of the housekeepers husband, Mervin Pugh, and former nanny Susan Savage about the house being difficult to navigate. "You don't know your way around real easy right off the bat...You have to open lots of doors. It has lots of ups and downs," and the basement entrance was hard to find.