I might have missed it but it would be worth knowing exactly what comments or behaviour is being investigated as a harassment and if this was widely shared or made privately to one person. Harassment covers a large range of behaviours.
Some posters have raised some points which could do with clarification.
If what CF said or has done is seen by the Police to come under harassment that causes alarm or distress (in a nutshell the test applied by Police here is would a normal person feel alarm or distress) or if it’s malicious communications (grossly offensive or threatening) then the Police are duty bound to investigate it. Yes, there are loads more important issues for them to deal with but they have to be impartial and not show bias by deciding what not to investigate so their hands are tied really.
Say someone reports CF for such an offence, they will have to show some proof of it like emails or actual evidence to back their complaint up which would then give the ‘reasonable suspicion ’.
The comment the Officer made about finding the evidence is more to do with proving what the person who made the report said by looking at CF’s laptop/computer.
Entering an address. The Police do not need a warrant to enter an address if they are there to arrest someone for an either an indictable or either way offence which harassment is, so yes they can use reasonable force to enter.
Police do need to have what is called a ‘necessity to arrest’ someone (as opposed to asking them to attend a station to be interviewed voluntarily) so in these circumstances seizing laptops as evidence would give them that necessity to turn up and enter CF’s address to arrest her. If they rang CF in advance to say they wished to interview her then it’s possible evidence can be destroyed or concealed.