Deeming was accompanied by his wife while in Australia, “a typical welsh lass,” Marie, née James.
Deeming had married her in Lower Tranmere, England in February 1881 and they had lived briefly at Birkenhead before leaving for Melbourne.
His brother Alfred, had married Marie’s sister, Martha.
By 1886 Deeming and Marie had two Australian born daughters, Bertha and Marie.
In 1888 his brothers Alfred and Walter learned that Deeming and his family were returning to England “with a considerable fortune”.
Later police and newspaper research discovered Deeming had been active in Cape Town, South Africa in 1888–1889, but his exact movements at this time are unclear and it appears he returned to Birkenhead, England, at least once. Marie had another child at this time.
He had arrived at Hull by November 1889, lodging in the nearby town of Beverley. Here he passed himself off as “a retired sheep farmer named Harry Lawson from Mount House Farm, Rockhampton, Queensland, living on 1,500 pounds a year.[11] He wooed Helen Matheson, the 21 year old daughter of his landlady and married her, bigamously, on 18 February 1890. About a month later, after a honeymoon in the south of England, he suddenly disappeared, taking his expensive gifts to Helen with him. Deeming’s wife and extended family had heard of his bigamous marriage to Helen according to Gurvich and Wray.
Deeming was later found to have then visited Marie and his (now) four children in Birkenhead. He apparently gave Marie several hundred pounds and announced he was leaving for South America. He would send for her and the children once he was settled.Before leaving he conducted another swindle at a jewellers in Hull. He was arrested for this on arrival at Montevideo and extradited back to England on a charge of “obtaining goods by false pretences,” being sentenced to nine months prison.
On his release from prison in July 1891, Deeming headed to the Liverpool area, settling into a hotel in the village of Rainhill, Merseyside under the name Albert Williams. A mysterious woman (almost certainly his wife Marie) who appeared at the hotel was dismissed as his “sister”, visiting before she left for Port Said. Deeming then took a lease on Dinham Villa, a house in Rainhill, supposedly on behalf of a military friend, a certain Colonel Brookes. However, Deeming himself took up residence at Dinham Villa, while a woman and several children seen at the house were again dismissed as merely his “sister and her children,” visiting, who had “since returned home.” Shortly afterwards, Deeming complained that the drains at Dinham Villa were defective, and the kitchen floor needed to be replaced. He closely supervised the work on the floor.
Following publicity surrounding the discovery of Emily Mather's body at Windsor, investigations at Rainhill revealed the decomposing bodies of Marie Deeming and the four children; Bertha (aged 9), Marie (7), Sidney (5) and Leala (18 months) buried beneath the re-concreted floor of Dinham Villa. The throats of most had been cut (Bertha had been strangled). The murder and burials had apparently occurred while Deeming (as Albert Williams) was courting Emily Mather, on or about 26 July 1891.