A troubled son snapped during the coronavirus lockdown and murdered his dad at the family home - and then wrote a note in blood explaining his actions.Nicholas Mooney, 23, killed James, 60, before taking his own life.It’s understood he stabbed his dad and then turned the knife on himself.Officers who arrived at their £300,000 home in upmarket Ralston, Paisley, last Thursday night found notes written in blood - and blood all over the property.Nicholas - who is understood to have suffered from mental health problems - also used an iPad to explain what he’d done.An area around the Lanfine Road property was sealed off as forensic officers combed it for clues.