Highway search in WA murder case

Sections of a Perth highway are being scoured for clues as police investigate the murder of Angela Rose MacKinnon.

The 55-year-old woman was found dead in her Gidgegannup home on March 10.

Her brother John MacKinnon, 42, has been charged with her murder and the attempted murder of Ms MacKinnon's 19-year-old son.

Police began searching the median strip on Tonkin Highway between Roe Highway in Forrestfield and Ranford Road in Forrestdale on Sunday morning.

A spokeswoman said the operation could take up to eight hours and was likely to slow traffic.