A psychiatrist who assessed the man who attached a fake collar bomb to a Sydney teenager believes the man was in a "psychotic state" when he did it, a court has heard.
But Jonathan Phillips told Sydney's District Court that did not mean Paul Douglas Peters's actions weren't well thought out when he broke into the Mosman home of schoolgirl Madeleine Pulver.
It's unusual for a person with a [trouble-free] life record to then move to commit an extraordinarily callous and dangerous act
Dr Phillips is giving evidence today at the sentencing of Peters, who admits strapping the fake bomb to the neck of Ms Pulver on August 3, 2011.
"intelligent and articulate" ... Paul Peters admits he strapped a fake bomb to Madeleine Pulver. Photo: Lee Besford
Attached was a note that Peters has now admitted was an extortion attempt.
Dr Phillips said that assessing Peters was as complex as any case he had tackled and there were times he struggled to understand what the former businessman was talking about, the court was told.
The court heard that electronic evidence showed Peters had edited two ransom documents contained on a USB stick attached to the fake bomb for a total of 503 minutes.
Madeline Pulver's parents Bill and Belinda arrive at court. today Photo: Jacky Ghossein
Dr Phillips said Peters may have been "intermittently psychotic over a period of time" leading up to the offence.
He said he believed Peters's account of not being able to recall the actual attachment of the device to Ms Pulver, saying people often had memory black outs "in situations of incredible stress".
The consultant psychiatrist described the offender as being both "intelligent and articulate", having lived "free of mental illness" for much of his life.
Madeleine Pulver had a device, which she believed to be a bomb, attached to her by an intruder.
"It's unusual for a person with a [trouble-free] life record to then move to commit an extraordinarily callous and dangerous act," he said.
However, during conversation about the book he was writing, his thoughts became disordered and fragmented.
"I found [him] very difficult to follow," the psychiatrist said, adding he had found the book to be nonsensical.
"Very difficult to follow" ... Paul Peters. Photo: AP
"He lost me when he began to talk about it."
Peters is expected to be sentenced later this year.
The hearing continues before Judge Peter Zahra.