32 I have reviewed the sentences imposed in this State for a single offence of murder, including Kowaleff v The State of Western Australia [2010] WASCA 183 (guilty plea, non-parole period of 26 years); Austic v The State of Western Australia [2010] WASCA 110 (not guilty plea, non-parole period of 25 years); Stasinowski (guilty plea, non-parole period of 24 years); Fraser v The State of Western Australia [2009] WASCA 23 (guilty plea, non-parole period of 27 years); The State of Western Australia v O'Kane [2011] WASCA 24 (guilty plea, non-parole period of 23 years); Cockram v The State of Western Australia [2011] WASCA 179 (guilty plea, non-parole period of 22 years); Lee (guilty plea, non-parole period of 21 years); Mack v The State of Western Australia [2014] WASCA 207 (not guilty plea, non-parole period of 20 years); Pedersen v The State of Western Australia [2010] WASCA 175 (guilty plea, non-parole period of 19 years); Butler v The State of Western Australia [2010] WASCA 104 (not guilty plea, non-parole period of 19 years); Zwerus v The State of Western Australia [2015] WASCA 174 (guilty plea, non-parole period of 18 years); Angliss v The State of Western Australia [2015] WASCA 8 (not guilty plea, non-parole period of 18 years); Johnston v The State of Western Australia [2012] WASCA 18 (not guilty plea, non-parole period of 18 years); Rosewood v The State of Western Australia [2014] WASCA 21 (guilty plea, non-parole period of 18 years); Stinson v The State of Western Australia [2014] WASCA 72 (guilty plea, non-parole period of 17 years); Prestidge v The State of Western Australia [2014] WASCA 16 (not guilty plea, non-parole period of 17 years); The State of Western Australia v Smith [2015] WASCA 87 (not guilty plea, non-parole period of 17 years); Silva v The State of Western Australia [2013] WASCA 278 (guilty plea, non-parole period of 17 years); Goodwyn v The State of Western Australia [2013] WASCA 141 (not guilty plea, non-parole period of 15 years); Wongawol v The State of Western Australia [2011] WASCA 222 (guilty plea, non-parole period of 14 years); Atherden v The State of Western Australia [2010] WASCA 33 (guilty plea, non-parole period of 14 years); Khan v The State of Western Australia [2013] WASCA 193 (guilty plea, non-parole period of 13 years).