When selling a real estate property, you are required to disclose to the possible buyer all potential problems that may affect the value of the property you are selling. Purposefully hiding known defects of your property is considered unlawful and criminal.
Different states follow different real estate disclosure laws. Being aware of the laws implemented in your respective state will help you when finalizing deals. Most states require you to present real estate disclosures in writing, signed and dated by both parties including the buyer as well as the seller. Most states require the property owners to make disclosures only on the problems they are aware of. They may not need to hire a professional inspector to look into the property for other potential problems that have not presented as yet. Other states such as California however, follow stricter laws requiring the owners to search for particular specified problems.
You are not required by the state to hire a professional inspector, however, doing so can be both advantageous and otherwise. If serious problems arise after the deal is closed, the report from the inspector is proof that you were unaware of the said problems at the time of the deal. However, if the inspector were to find new faults that you were unaware of which may decrease the value of your property, you are required by law to report them.
You may close a deal well on your own, but it is may be best to consult with a real estate attorney or broker before doing so, because of the large sums of money at stake. An attorney will also provide you with a better understanding of the real estate laws prevalent in your state.