I live in Tenerife, i never have any problems [probably because I'm in bed most nights by 12pm] , having stated that if you arrive on the island thinking the police are their to help you " forget it "[they tend to treat all tourists with contempt because of drink / drug issues],having stated that behave yourself take the same precautions you would do on a night out in Manchester you will be fine. I'm sad to learn about Lee I hope his family find justice.