Daniel Boulton, 30 - a former amusement arcade worker - faces two life sentences after he was found guilty at Lincoln Crown Court on Wednesday on two counts of murder.
After the sentencing, Pc Steve Denniss relayed the dramatic moments leading to Boulton's arrest.
He told how walking his dogs in Hubbard’s Hill, near the Hallington entrance, on June 1 last year when he saw a man sat on a bench in a hooded top.
He immediately realised this man was Daniel Boulton - one of Lincolnshire’s most wanted men, who was wanted for the murder of Bethany Vincent, 26, and her son Darren, aged 9, known as DJ.
Both mum and her son sadly died after receiving stab wounds at their home in Louth in May last year.
The off-duty officer began to let go of his dogs’ leads and approached Boulton, who responded by attacking him by kicking and punching him.
Boulton, who had walked from Skegness before murdering his victims, then ran off and PC Denniss chased him, calling an on-duty colleague for back-up at the same time.
It was then Boulton turned back, pulled out a knife, demanded PC Denniss' phone. and stabbed the officer in the leg. Thankfully, the injuries were minor and he was later treated by ambulance crews.
Despite his injury, Pc Denniss continued to chase Boulton before other officers arrived at Hubbard’s Hills and were guided towards Boulton’s location. Pc Denniss then assisted in clearing the public from the area for their safety.
Officers continued to pursue Boulton, before he was tasered and arrested.
Pc Denniss said: “I didn’t take into account that I was putting my life at risk; I just saw one of the most dangerous offenders I have come across in my 20 years of policing and knew I had to do something.
“I really need to praise the firearms team and other officers who arrived within minutes and who continued the foot chase and arrested Boulton a short time later at a near-by farm. This to me was a massive team effort.
“I know that this is a devastating incident in which a family have very sadly lost their loved ones, but I am pleased that I could help bring some justice to them.”
The team effort has been recognised within Lincolnshire Police and much praise given to Pc Denniss and the team that assisted.
Assistant Chief Constable Kerrin Wilson said: “My heartfelt condolences go to the family of Bethany and DJ. This was an horrific attack on a mum and her child, and I cannot imagine what they must be going through.
“Although we sadly cannot change what took place in this tragic case, I would like to thank Pc Denniss and the team that helped apprehend Boulton. I would also like to thank the investigation team, and the Crown Prosecution Service which has done a great job in bringing justice to the family.
“Pc Denniss put his life at risk to ensure this dangerous man was arrested. His commitment, professionalism and bravery is commended and he is a credit to our policing family.”
Boulton's trial concluded in its third week. The jury heard that he carried out the brutal killings just a day after sending his former girlfriend a text which read “nightmare on Holme street.”
Boulton calmly smoked a cigarette in the garden after carrying out the murders and walked away leaving an unharmed but “distressed” nine-month-old child crawling around the house.
He then then led police on a manhunt until the following day, burgling a cottage where he stole alcohol and food, and stabbing an off-duty police officer in the leg in the Hubbard’s Hills area of Louth.
He was tasered and arrested at a nearby farm in Hallington after trying to hijack two cars and encouraging armed officers to shoot him.
Boulton, who did not give evidence during his trial, admitted manslaughter but denied the two murders – telling a psychiatrist “autopilot did the job for me.”
However, the jury rejected Boulton’s case that “he lost control” due to his personality disorder and took just two hours to convict him of both murders.