Paul Thijssen purchased hammer at hardware store, rented car before killing Lilie James

The sickening lengths Paul Thijssen went to in planning the murder of Lilie James can be revealed as police continue to investigate his movements and mindset in the lead up to the shocking crime which rocked the city.

School killer Paul Thijssen made a trip to a hardware store and borrowed a car the morning of Lilie James’ murder which police believe was premeditated and not an impulsive crime.

The sickening lengths Thijssen went to in planning the St Andrew’s Cathedral School’s water polo coach can be revealed as police continued to investigate his movements and mindset in the lead up to the shocking crime which has rocked the city.

Police now believe Ms James’ murder was not impulsive, but that it was chilling and calculated by the man she had dated for just five weeks before calling it off days earlier.

Thijssen, 24, a former student at the elite private school who was then employed as a sports co-ordinator, was captured on CCTV last Wednesday morning purchasing a hammer at a hardware store in the city’s east, close to his Kensington home.

Paul Thijssen intended to kill Lilie James that night.

Lilie James’ death came days after she called off her relationship with Thijssen.

The Daily Telegraph understands the hammer is not the one that was used to kill Ms James. Police believe Thijssen armed himself with two hammers, one which may have come from a school store room.

The Dutch national did not own a car, but police have discovered he rented one that day and drove it to work at the school.

“The assumption would be that he knew he needed a car to get away quickly afterwards, and particularly to get to where he went,” a source close to the investigation said.

Paul Thijssen arrives at Vaucluse in the hours following the death of Lilie James. Picture: Supplied

Ms James, 21, was bashed to death in a bathroom inside the school’s gym area, around 7pm that night. The popular young staff member was returning sports equipment after an off-site training session, when Thijssen followed her into the bathroom.

Confronting CCTV from inside the school shows Thijssen standing outside the bathroom door holding a hammer, preparing to barge in.

The Daily Telegraph can reveal the chilling and precise information Thijssen told a triple-0 operator when he called later that night to alert police to Ms James’ body, just before midnight.

The floral tributes at St Andrews School after Lilie James was murdered last week. Photo: NCA Newswire /Gaye Gerard

In an urgent dispatch message sent out to police by the operator, the message stated: “Informant says there is a body in a bathroom on the right-hand side in reception area. Through reception and to the left. Informant says he was there a couple of hours ago. Female body”.

But in a sickening act, Thijssen had already used his dead victim’s phone to text her father Jamie James to ask him to come and collect her from the school.

Mr James arrived at the Kent St building before police, but wasn’t able to get inside because the glass front doors were locked.

Police suspect Thijssen jumped to his death from a cliff in Vaucluse soon after he called police.

A close friend of the James family said last night no funeral plans had been made yet.