A Baldivis woman is the third person to be charged over an alleged arson attack at a business in Port Kennedy.
The blaze destroyed seven vehicles at the commercial premise on the corner of Paxton and Fielden Ways, on June 14 leaving a damage bill of $200,000.
A 32-year-old man also from Baldivis and a 32-year-old Warnbro woman have also been charged over the blaze.
The investigation is ongoing, and officers urge anyone with any information relating to this matter, to contact Crime Stoppers on 1800 333 000 or online at www.crimestopperswa.com.au
Rewards of up to $25,000 are available for information that leads to the identification and conviction of an arsonist.

Bushfire readiness takes centre stage at City of Kwinana's free Summer Sounds festival
WA Open Golf Championship to tee off at Secret Harbour Golf Links
Halls Head named WA's most persistent storm damage hotspot
Four illegal e-bikes to be crushed after police crackdown in Halls Head, Falcon
Aboriginal jobs and careers expo to attract 1000 attendees in Rockingham
Firefighters attend Lakelands home after reports of thick smoke
WA Government to ban screen use for younger students as part of six-month trial
Singleton General Store shutdown over illicit tobacco, vape sales
Concerns for missing Bertram woman
