Police ripped up carpet and dug up parts of the backyard of the accused Claremont serial killer's former home in an attempt to uncover clues, it has been revealed.

During testimony in the triple-murder trial, WA Police cold case forensic supervisor Colin Beck said police executed three simultaneous property search warrants the morning of Bradley Edwards' arrest on December 22, 2016.

The 'crime scenes' were established at Mr Edwards’ Kewdale home, his parents’ former Huntingdale home where he lived after his 1997 divorce, and his parents’ Halls Head home. Mr Edwards' former work car was also seized that day from its new owner.

About one month later, Sergeant Beck said the home Mr Edwards shared with his first wife between 1991 and 1997 was stripped bare.