Police are searching for three thugs who assaulted a man in Armadale last month before trying to steal his trail bike.
The 19-year-old was riding an off-road trail bike with a friend at the corner of Twelfth Avenue and Tonkin Highway on March 15.
He noticed two other bikes in the area after he became separated from his friend about 5pm.
A police spokeswoman said the two riders started chasing him before one of the bikes was driven up alongside him.
“The victim felt a blow to the back of his helmet by an unknown object, causing him to fall off his bike and lose consciousness,” she said.
“When he regained consciousness, one of the offenders was trying to start his bike.”
He managed to push the thief away and fled on his bike.
The first bike was a 125cc four-stroke black trail bike in a bad condition.
The male rider is described as aged 16 and 165cm tall with dark skin, a solid build and brown wavy hair with blonde streaks.
He wore a green motorcross helmet, a red shirt, black shorts and white shoes.
The second bike was a 250cc four-stroke white motorcross trail bike.
The male rider is described as aged 20 and 180cm with fair skin and a slim build.
He wore a white motorcross helmet with a cannabis leaf on it, a green shirt, a thick gold necklace, black shorts and red socks.
The male pillion passenger on the second bike is described as aged 14 and 165cm tall with dark skin and a slim build.
He had crooked teeth, green eyes and a scar on his right forearm. The boy wore a black shirt, red shorts and black shoes.
Anyone with information should call Crime Stoppers on 1800 333 000.