Old school records about the brothers who died in what police are investigating as a murder-suicide alongside their parents paint them as cheerful, social boys who loved spending time with friends and taking part in school activities.

Leon, 16, and Otis, 14, were found dead alongside their parents, Jarrod Clune, 50, and Maiwenna Goasdoue, 49, about 8.15am on Friday at their family home on Mott Cl in Mosman Park, an affluent western suburb of Perth.

Three pets — two dogs and a cat — were also found dead in the property.

A support worker who provided care services for the boys arrived at the home and found a note containing words to the effect of “don’t enter” and “call police”, before alerting authorities.

Police are treating the incident as a double murder-suicide and said both children had “experienced significant health challenges”.

It is understood that both boys lived with autism and had attended Christ Church Grammar, a top private school in Perth, where their father is also believed to have studied.

Previously published school newsletters describe the brothers as enjoying everyday childhood activities, offering a glimpse of who they were long before the tragedy.

“I liked going down to the beach and eating fish and chips with tomato sauce at Cicerello’s,” Otis wrote in 2017, when he was in pre-primary.

“I have liked exploring the river with my friends. I have also liked swimming lessons and trampolining,” he wrote two years later.

A teacher described Otis as “a lovely member” of the class who was able to independently carry out his morning routine.

“Your warm greeting every morning makes my day!” the teacher wrote.

Four years later, Otis was praised for being keen to engage with classmates.

“Otis, you have demonstrated an eagerness to engage with your peers during group activities,” a teacher wrote.

“I am impressed that you are using your device to communicate during phonics. Well done for participating so enthusiastically at Bounce and for completing your Talk for Writing text.”

Leon was described by his teachers as “a happy and enthusiastic student who has shown increasing maturity”.

“Leon is to be commended on his hard work throughout this year and for the way he has tackled his academic and social goals,” a teacher wrote in 2016.

“His cheerful personality is very much appreciated by all of us.”

As a Year 1 student then, Leon said his favourite moments included making popcorn to learn adjectives and creating “coco-pop crackles” during science lessons.

In 2019, he wrote that his favourite part of the year was “playing with my friends on the oval”.

“This year I learnt how to communicate with my device,” he said.

“I love sitting with my friends during chapel and assembly.”

The boys’ father was also mentioned in a school newsletter in 1991, which described him as “a versatile player”.

“Jarrod Clune — What he lacked in skill, he made up for with sheer persistence and endeavour,” the newsletter wrote.

Detective Inspector Jessica Securo said the family had no reported history of family violence with police.

“It’s not often that our officers come across such a tragic event with this many persons deceased,” Securo said.

WA Premier Roger Cook described the incident as an “unimaginable tragedy that will ripple throughout the community and the entire state.”

“That the lives of two innocent children have been taken is heartbreaking,” he said in a statement.

“I urge anyone who is struggling to seek help.

“I want to offer my deepest condolences to all those affected and thank the first responders who attended what would have been an incredibly confronting scene.”

The cause of the family’s deaths is yet to be confirmed, as detectives speak with neighbours and examine CCTV to piece together the family’s final hours.