A PERTH man who was given one of the longest sentences in WA history for the brutal home invasion murders of a mother and daughter has lost an appeal.

Lesley Jonathon Cameron was sentenced to 32 years in prison for the horrific murders of Maureen Horstman, 67, and her 26-year-old daughter Tamara Horstman at their home in Warwick in 2013.

Cameron launched an appeal against his sentence, with his lawyers arguing it was “manifestly excessive” and sentencing judge Justice Eric Heenan made a mistake when he described the crime as being in the “worst category” of murder cases.

It was also argued the judge did not give sufficient weight to Cameron’s early guilty pleas and a psychiatric report.

Justice Heenan likened Cameron to an animal when he broke into the women’s Warwick home in December 2013 and bludgeoned them with a hammer in their bedrooms before covering their faces and stabbing them with a pair of scissors.

Cameron, who was 19 at the time, also raped Tamara Horstman after hitting her with the hammer – a violation the judge said “can only be described as bestial conduct”. It is not known if Tamara Horstman was dead or alive but unconscious at that stage.

Cameron’s lawyer told the court during sentencing his client was “drug-addled” at the time and confessed to police to being high on speed and ice, describing himself as a “walking time bomb”.

In a Court of Appeal decision on Wednesday, three judges unanimously agreed to dismiss Cameron’s appeal.

Justice Michael Buss said the sentencing judge was right to characterise the murders as being in the “worst category”.

“Although worse murders can be imagined, the seriousness of each of the murders committed by the appellant ... required the conclusion that the murders were within the range of the ‘worst category’ of cases of murder,” he said.

“The minimum term of 32 years for each count of murder was within the range open to his Honour on a proper exercise of his discretion. The length of each minimum non-parole period was high, but was not unreasonable or plainly unjust. The periods were not manifestly excessive.”

Cameron will be 51 years old before he is considered eligible for parole in 2045.