A putative father who has a reasonable basis to question paternity can compel genetic testing, even if it is not in the child’s best interests, the New Jersey Supreme Court held on Wednesday.

The court discarded a 20-year-old standard that made the child’s interests the deciding factor, finding it could not be reconciled with intervening changes to the Parentage Act that allow denial of genetic testing only for good cause.

Although the best-interests standard governs most decisions involving children, it cannot be determinative in this context because “in many, if not most, cases where genetic testing is ordered to refute a presumption of paternity, some destabilization of the child’s life is inevitable,” Justice Barry Albin wrote in D.W. v. R.W., A-4-11.

His opinion sets out guidelines for trial courts deciding what constitutes good cause, and best interests is merely one factor to be taken into account.

Among the other factors: how long the person seeking the test has believed himself to be the father; how the possibility of nonpaternity was discovered; the relationship between the child and the presumptive father as well as with the alleged father; the age of the child; and the child’s interest in knowing his or her genetic background.

Applying the factors to the case at hand, the four-justice majority found no good cause to deny the testing.

The lone dissenter, temporarily assigned Appellate Division Judge Dorothea Wefing, said that if the testing was not in the child’s best interest — which must remain the “fundamental guiding principle” — that should suffice as good cause to deny it, “except in the most extraordinary of circumstances.”

M.W., the child in question, referred to by the pseudonym “Mark,” was 19 years old when his presumptive father, R.W., or “Richard,” sought the testing in the course of an acrimonious divorce from his wife, D.W., or “Diane.”

When Diane filed for divorce in late 2006, Richard counterclaimed with claims of infidelity and emotional distress for hiding from him that Mark was not his biological son.

He also asserted a third-party claim against his sister’s former husband D.B., or “Donald,” asserting he was the real father and demanding reimbursement for the money he spent raising Mark.

Diane had admitted to Richard that she had sexual relations with Donald in the latter part of the summer of 1986. Mark was born April 27, 1987.

Richard had also tricked Mark into providing a DNA sample that showed, through home DNA testing, that Mark was not his child, but those results were not admissible.

In May 2007, Richard moved to compel genetic testing to support his parentage claim.

After a hearing, Morris County Superior Court Judge Stephan Hansbury denied it, saying Richard had not presented clear and convincing evidence that it was in Mark’s best interest.

He relied on M.F. v. N.H., 252 N.J. Super. 420 (App. Div. 1991), which held that a court could not order paternity testing without clear and convincing evidence that it is in the best interests of the child.

He then threw out the claim against Donald because it could not succeed without genetic testing.

The Appellate Division affirmed, also citing M.F.

In finding that the lower courts had erred, Albin pointed out that neither mentioned N.J.S.A. 9:17-48(d), which governs when genetic testing can be ordered for purposes of proving paternity, and makes no mention of best interests.

Albin traced the history of the law from its enactment in 1983, when it said a court “may require” submission to testing. That version was in effect when M.F. was decided in 1991.

A 1994 amendment replaced “may require” with “shall require,” making it harder for a judge to say no to a testing request.

The current language, the result of a 1998 amendment, further limited the court’s ability to refuse testing, saying it can be denied only for “good cause,” without defining the term or providing guidance on how to decide if it exists.

In Wednesday’s opinion, the court filled that gap, supplying the factors to be considered and then applying them to reverse and remand.

“This case is not about the wisdom of a father proceeding with a parentage action in the circumstances presented here, but about his legal right to do so under the statute,” wrote Albin, joined by Chief Justice Stuart Rabner and Justices Jaynee LaVecchia, Helen Hoens and Anne Patterson.

He discussed a wide range of factors, including Richard’s timely filing of the parentage action after learning he had reason for doubt; Mark’s estrangement from Richard and his testimony at deposition that he had no desire to reconcile; Richard’s stance that he had an inherent right to know whether he was Mark’s father; and Mark’s age, now 25, which Albin said made him “better equipped to handle such news than a young child.”

In addition, Mark would suffer no financial harm if Richard was not his father since Richard would try to recoup the money from Donald.

In addition, Albin noted that any parentage action filed by Richard after Mark turned 23 would be barred by the act’s statute of repose and that allowing Mark to choose the time of testing “would permit him to run the clock out and extinguish Richard’s claim.”

In fact, Albin pointed out that Mark had texted Richard telling him, “I will testify against you so you don’t win.”

Thomas Snyder, who represents Richard, says the ruling is a significant one for providing judges and lawyers with “a road map to follow in addressing these really complicated issues.”

From a personal perspective, however, “it’s a sad thing. These are people’s lives,” remarks Snyder, of Einhorn, Harris, Ascher, Barbarito & Frost in Denville.

Mark’s lawyer, Clark solo Robert Ricci Jr., calls it “a sad day when the monetary interests of the father trump the interests of the child,” adding that the stigma and harm to Mark were greater than the majority took into account.

“Under what circumstances would somebody not be able to get a paternity test?” he wonders.

John Paparazzo of Riverdale, Donald’s attorney, was in court and could not be reached for comment.