Tyler Hadley considered a number of murder weapons to kill his parents back in 2011.
That was one revelation in court Friday as day five of Hadley's sentencing hearing concluded.
For more than six hours, the focus was on Dr. Wade Myers, a forensic psychiatrist from Brown University. He said a "severe mental illness" is why a young man with good parents went and killed them.
Dr. Myers said the drug Celexa, while not the cause of the crime, may have played a part based on potential side effects.
"I think it amplified the suicidal and homicidal thinking he (Hadley) was having," said Dr. Myers.
During cross examination, prosecutor Tom Bakkedahl tried to point out inconsistencies on what Tyler Hadley told Dr. Myers and what he told another doctor after the murders.
Bakkedahl asked Dr. Myers if Tyler Hadley considered using other things besides a framing hammer to kill his parents.
"Did he (Hadley) tell you he considered a hatchet?" asked Bakkedahl. " Yes that's right," was the response. "How about a kitchen knife? came the follow up question. " He considered that yes," was Dr. Myers reply.
Dr. Myers said at the time of the crimes, Tyler Hadley had major depression with psychotic features.
The prosecution pointed to a psychological test afterward where Tyler answered 'false' to the question did he (Hadley) have severe psychological problems and that perhaps Dr. Myers was being manipulated.
The hearing will resume Monday with the another mental health expert for the defense.