We lived in East Berkshire for 15 years, not far from Broadmoor. Every Monday at 10.00m they would test the sirens.
If they went off at any other time we knew there had been an escape. Most escapees were low risk patients, close to release, some walked out because they did not want to be released and hoped an escape would mean they would be kept there. They usually escaped away from the village towards the nearest town and railway station, but usually ended up knocking on a door the next village on and asking for a cup of tea. The houseowner would ring the police who would just come round and collect them.
I can only remember one dangerous one . A man got out early one morning, so all the schools closed. It was a stiffling hot day as we were in the middlee of a heatwave and as most escapees were not violent or dangerous when we got home as we had a secure fence around the garden, I allowed the children into the garden, with strict insructions to come in if they heard anyone the the other side of the hedge. I was also keeping a very close eye on them.
12 hours after the escape it was announced that the escapee was a child rapist. I was furious as were other parents who had done much the same with me. If we had known, we would have stayed in doors even if we stifled. he was free for about 2 days, but did no one any harm.