The mother of PC Andrew Harper says she hopes for an "easier" year following the anniversary of her son's death.
PC Harper, 28, died when he was dragged for more than a mile along a road by a getaway car on 15 August 2019.
Debbie Adlam said a memorial service held for her son on Friday had been "very emotional".
She said campaigning for tougher sentences for killers of emergency services workers had given her something to focus on.
The private service at the Thames Valley Police training centre in Sulhamstead, Berkshire had been attended by the officer's family, close colleagues and Chief Constable John Campbell.
Mrs Adlam said: "The service was very emotional. I found it a lot more difficult than I was expecting.
"It kind of caught up with me a little bit, to see his name on the stone at the bottom.
"I'm hoping the next year will be slightly easier with the court being done. At the same time, he's not coming back and we've got to get used to the idea now."
Newlywed PC Harper, from Wallingford in Oxfordshire, died after his feet got caught in a tow strap trailing behind a getaway car that had been used to pull a stolen quad bike near Stanford Dingley in Berkshire.
Henry Long, 19, Albert Bowers and Jessie Cole, both 18, were convicted of manslaughter but cleared of murder following a trial at the Old Bailey in July.
Long, who was the driver, was jailed for 16 years, while passengers Bowers and Jessie Cole were sentenced to 13 years each.
Their sentences have prompted PC Harper's widow, Lissie, and Mrs Adlam, to campaign for tougher prison sentences for the killers of emergency service workers.
Mrs Adlam said: "The last couple of weeks, we have been focussing on doing something positive to try and get either the law or sentencing guidelines changed so I've been a lot busier.
"We have a goal in Andrew's name which gives you the drive to keep persevering but, take that away, and we are muddling through as much as we can."
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