IT S the nightmare scenario. Your family is at home asleep when you hear a noise downstairs. Could it be an intruder? And, if so, are they armed? What should you do? How far should you go in protecting your home and family? As high-profile cases such as t

IT'S the nightmare scenario. Your family is at home asleep when you hear a noise downstairs.

Could it be an intruder? And, if so, are they armed? What should you do? How far should you go in protecting your home and family?

As high-profile cases such as that of Norfolk farmer Tony Martin - who shot an intruder in 1999 and was jailed - have shown, it is a controversial issue.

Newham crime prevention officer Pc Brian Walker says: "You do have the right to use reasonable force to protect yourself (or another person) if you are in imminent danger, or indeed make a 'citizen's arrest', but it is best to think about your own safety, and the safety of others, in your home.

"The thief may escape, hopefully empty-handed. Just make sure you call police immediately. It is much easier to search for a suspect at night."

He added: "Remember, a night-time burglar wants to be as quiet as possible. Believe it or not, but the last thing an intruder wants to do is to wake up the occupants. They don't want anyone to see them and call police.

"If you think you hear a strange noise at night, turn on the lights, call out. If there is anyone there this will scare him off."

Put a few plants or ornaments on the widow sill, he said, they will make the intruder think twice about trying to climb in.

With the weather improving, Pc Walker advises people against leaving unguarded windows open for ventilation.

"If you have a ground floor bedroom you need to be especially careful. Even leaving a small window open can be risky. Would it be possible to reach in and open a larger window - have you fitted window locks to stop this happening?

"You might also be surprised that some burglars can get through very small gaps - it is best not to take the chance."

He went on: "If you are lucky, your window may be fitted with a catch that allows it to be locked open, leaving a small gap for fresh air to get in. This is a standard fitting to most double glazed units these days.

"Otherwise you may need to think about fitting some sort of restricting device. If you have 'sash' windows you can fit sash window stops to either side of the window. These will allow the window to be opened a few centimetres, but no more.

"For conventional 'casement' windows you could fit a window 'stay'. These are often fitted to nursery windows to prevent the window opening wide enough for a toddler to fall out. They work equally to prevent the window being forced wide open.