Trouble with 'displaced residential occupier' (s77(a) of the Criminal Justice Act 1977) is it is such a faff. The occupier has to be within the category of 'occupier' covered by the section and he has to find a commissioner for oaths or notary public to sign a statement that he is so, then go back and have the statement served on the squatter(s), and only then, if they refuse to leave, can the squatter(s) be arrested. Under the new law it will surely be enough for the police to suspect squatting and ask the supposed squatters to give an explanation for their presence in the property; in the absence of any lawful excuse being shown, they will be arrested and charged. The owner need not even know that squatters are there, nor need the owner or tenant need to show that he is an occupier and is 'displaced', requiring the property for his residential occupancy.