Peter Parry wrote
Nightjar wrote

A DIY alarm won't be remotely monitored by a professional
company and those are the only alarms that really act as a deterrent.

Class A alarms, usually found in commercial premises, are the only
ones properly monitored and which will produce a police response.

That's just plain wrong. If you monitor it yourself, and check the
video and see a burglar there and not just some cat etc, that will
certainly produce a police response when you ring them and tell
them that you can see the crim trying to get into your house.

Most domestic "monitored" alarms are Class B Auto
diallers such as used by ADT on their cheaper offerings.

This is DIY, no need to worry about that sort of inadequate
service which will cost a lot more than a DIY system.

Even assuming the incoming scrote forgets to disable it on entry

And with a DIY system, he wont be able to do that.

all it does is phone the receiving centre who simply phone
the contact they have. They don't alert the police.

All the more reason to monitor it yourself and call the cops
and tell them that you can see the crim trying to get in to
your place and have them show up and nab the crims.

As most alarm companies (including even ADT) offer both class
A and Class B installations it isn't possible to tell if a house has
a Class A alarm with police response from the outside.

And impossible with a DIY system done properly.