Police have charged Ross Boag, the third man believed to be involved in the death of Peta Fairhead, who died on Wednesday after being dumped outside Joondalup Hospital with significant injuries.
Mr Boag was arrested, three days after two other men, Lucas James Yarran, 20, and Leroy Daniel Smith, 19, faced court charged with the mother-of-three's kidnapping and murder.
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Ross James Boag has been found
Ross James Boag has been located and taken into custody. Vision: Nine News Perth
WAtoday understands Mr Boag, 19, who is known to the other men, was arrested on Monday around midday.
He has since been charged with three counts of armed robbery, three counts of kidnapping and
one count of murder.
![Ross James Boag (left) was arrested by police in relation to Peta Fairhead's death on Monday. Leroy Daniel Smith (right, ...](/web/20160811152407im_/http://www.smh.com.au/content/dam/images/g/q/m/9/3/r/image.related.articleLeadwide.620x349.gqnonu.png/1470650197570.jpg)
He is due to appear in Joondalup Magistrates Court on Tuesday.
The two other men are accused of storming a home where Mrs Fairhead was and stealing her jewellery and mobile phone while threatening her and being armed with a baseball bat and machete.
They are accused of afterwards pushing Mrs Fairhead out of a car with significant injuries and leaving her to die outside the emergency unit of Joondalup Hospital about 3.15am on Wednesday.
She leaves behind two young sons and a daughter.
![Young mother Peta Fairhead was described as loving and caring by her friend Danielle Hayden.](/web/20160811152407im_/http://www.smh.com.au/content/dam/images/g/q/l/9/w/w/image.related.articleLeadwide.620x349.gqnonu.png/1470650197570.jpg)
Mrs Fairhead's friend Danielle Hayden on Thursday described her as a caring and loving person who was always smiling, laughing and "helping other people".
"I don't know why or who would do this to you," she said.
"You have left behind so many people that will miss you and your beautiful face.
"I will always love you."
Ms Fairhead had reportedly moved to Secret Harbour from the Wheatbelt town of Quairading only a few months ago.