A Greenfields business owner and his son have been charged over the alleged assault of a would-be thief.

The man allegedly attempted to ram raid the Mower Magic store on Rouse Road with a stolen Isuzu ute around 7.20pm on April 3.

He then loaded a number of items into the ute.

During the incident the 38-year-old man was detained by the business owner and his son.

Police allege the men used excessive force to detain him.

Actively defending your property should be your right, the force necessary to protect yourself, your family and your property should be deiced by you. Not the government and not the police. The law needs to be change so criminals are not protected while they are breaking the law.