A man has been convicted over the death of a 100-year-old woman whose neck was broken in a street robbery in Derby.

Artur Waszkiewicz knocked Zofija Kaczan to the floor on Empress Road, Normanton, while snatching her handbag as she walked to church.

Kaczan, who was born in Poland and survived a Nazi labour camp during the second world war, sustained multiple injuries in the attack on 28 May last year, including a fractured neck and cheekbone. She died on 6 June of pneumonia brought on by her injuries.

Jurors at Derby crown court deliberated for just over two hours before unanimously finding Waszkiewicz guilty of manslaughter and robbery. Addressing the jury, the judge said: “The sentence will inevitably be one of lengthy imprisonment. Mr Waszkiewicz knows that.”

Artur Waszkiewicz, who denied manslaughter and robbery, claimed he had found Kaczan’s handbag in the middle of the road. Photograph: Derbyshire police/PA

CCTV showed Waszkiewicz driving a Seat Leon car he had bought from his father minutes before robbing Kaczan. He slowed down as soon as he saw a “small, vulnerable” woman on her own, the prosecution said. He needed an “easy target” to steal from so he could meet a drug dealer a short time later to buy £20 of heroin.

Opening the case, Kate Brunner QC, prosecuting, said: “She was attacked, she was thrown to the ground and her handbag was snatched from her. She was small, on her own, vulnerable – an easy target for a man desperate for money. He attacked Ms Kaczan, yanking her handbag from her and leaving her injured in the road and driving off.”

Police arrested Waszkiewicz, who was also born in Poland, after his fingerprint was recovered from a receipt in Kaczan’s bag. He fled Derby after the incident and hid under a bed at his mother’s house in London to try to avoid arrest. He changed the insurance details on his car and changed his appearance by cutting his long hair.

The jury heard he had been so desperate for cash that he had tried to sell his dog, and asked a neighbour for money.

The trial was told the 40-year-old had previous convictions including shoplifting, creating false identification documents and battery.

He denied both charges, saying he had found Kaczan’s handbag in the middle of the road, picked it up, and disposed of it at a well-known fly-tipping area because there was no cash.

A spokeswoman for St Maksymilian Kolbe, the Polish church Kaczan attended, said: “We would like to thank all the people who have been involved in bringing the perpetrator of the crime against Zofija Kaczan to justice.

“Mrs Kaczan was an active member of our community, who although she had reached the milestone of 100 years, enjoyed her life going to church, shopping, having her hair done and attending the lunches at the Polish centre followed by bingo.

“She had a very difficult early life. Coming to Derby in 1949, she had found a degree of stability and tranquillity. That tranquillity was shattered by the brutal events of May 28 2018.

“Despite the pain and suffering that she was in for the last week of her life, she had the capacity to pray for her attacker before she died.”

Kaczan’s friends paid tribute to her, saying she did not want to celebrate her 100th birthday because it was on the same day of the year she had been sentenced to death by the Nazis.

Waszkiewicz, of Shepherd’s Bush in west London, will be sentenced at the court on Thursday.