A driver has admitted causing a crash that claimed the life of a young off-duty ambulance officer.

Sean Dickey, 22, was riding a motorbike with a friend when they were struck by a car at the intersection of Halswell Rd and Aidanfield Drive in Christchurch on April 19 this year.

Emergency services who rushed to the scene at around 6.45pm that day were devastated to find one of their colleagues was involved in the crash.

Dickey, originally from Wanaka, passed away, devastating "the proudest parents you could imagine".

Four months later, police laid charges against Anja Jacoba Maria Hermina Derks, a 60-year-old from Christchurch.

As well as a charge of careless driving causing Dickey's death, she also faced a charge of operating a vehicle on Halswell Rd on April 19 carelessly and causing injury to another man.

At Christchurch District Court this afternoon, Derks entered guilty pleas to both charges.

Community Magistrate Simon Heale convicted Derks and remanded her for sentencing on October 17. He referred the case to be considered for a restorative justice conference, where Derks would meet with the family members of the victims to talk about what happened. Heale also called for a reparation report to be prepared.

A summary of facts outlines how the tragedy played out on the evening of April 19.

At around 6.45pm, Dickey and a friend were riding motorbikes northbound on Halswell Rd.

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Derks was driving home in the opposite direction in a Ford Endura.

The motorcyclists were approaching the intersection of Halswell Rd and Aidanfield Dr, which has a posted 80km/h speed limit.

Dickey was the lead rider and wearing high vis. His friend was wearing predominantly dark clothing with less reflective material, the summary says.

They were travelling at 80km/h.

Derks slowed as she approached the intersection to turn right into Aidanfield Dr, slowing to 26km/h as she started to cross the lane for oncoming traffic.

The police crash investigation report suggests she was "making an unhurried turn at the intersection... that behaviour is consistent with the driver having looked but failed to see the approaching motorcyclists".

Dickey was about 43m from the intersection as Derks begun to cross his lane.

He braked and skidded for .44 seconds and tipped the motorbike over to its left.

He struck the front passenger's corner of Derks' car.

Dickey has ended up under the middle of the car.

His friend was hit by Derks' front door and he's landed near the gutter.

Dickey suffered high energy impact injuries to his chest, abdomen, and pelvis, as well as crushing to his chest. He died from his injuries at the crash site.

The second victim suffered a broken femur and fractured heel.

After the crash, Derks was in "shock and disbelief, shaking and hyperventilating", the summary says.

She told a person on the scene that she didn't see the motorcyclists and couldn't understand what had happened.

"She was very concerned about the motorcyclists, asking how they were," the summary says.

Derks co-operated with a blood test which detected nil alcohol or impairing drugs.

She has not appeared before the courts before.

After his death, father Steve Dickey told the Herald that his son, who first joined the St John cadets when he was 6 years old, "spent his whole life doing things for others".

His position at St John was his "dream job", Steve Dickey said.

"He was just a lovely guy. Always worrying about people and trying to help."

St John Canterbury ambulance district operations manager Curt Ward earlier said the devastating loss has been widely felt across St John.