An heir to the one of the world's largest chemical companies avoided jail time for raping his 3-year-old daughter after the judge decided he "will not fare well" in prison, the News-Journal reported.

In her ruling, Judge Jan Jurden said she considered the circumstances of the case and decided Robert H. Richards IV would benefit from treatment instead of prison -- a sentence typically given to drug addicts.

In 2009, Richards' rape case became public after his ex-wife filed a lawsuit seeking damages for abusing his daughter. In the suit, she claims Richards admitted to sexually abusing his infant son between 2005 and 2007 -- the same time period where he raped his daughter.

In 2010, police investigated the claims but said they did not have enough evidence to justify charges. According to the News-Journal, authorities will take a second look at the allegations.

"It's an extremely rare circumstance that prison serves the inmate well," said Delaware Public Defender Brendan J. O'Neill, who is not involved in the case. "Prison is to punish, to segregate the offender from society, and the notion that prison serves people well hasn't proven to be true in most circumstances."

O'Neill added he's seen lawyers argue their clients are too ill or frail for prison, but has never seen a judge cite the reason that as a reason to not send someone to prison.

He said the case may cause the public to become skeptical about "how a person with great wealth may be treated by the system."

Jurden, who has been a judge since 2001, has not commented on the ruling.

Richards is currently unemployed and supported by a trust fund. In 2005, he purchased a $1.8 million mansion in Greenville and also owns a home in Rehoboth Beach. His great-grandfather is billionaire Irenee du Pont and his father is Robert H. Richards III, a retired partner in the Richards Layton & Finger law firm.