The Supreme Court ruled Thursday, by a 7-2 vote, that states may demand a mentally ill defendant who wants to lead his own defense to accept the assistance of a lawyer.

The decision nullifies an Indiana Supreme Court pronouncement that stipulated a criminal defendant who is found sufficiently capable to stand trial should be allowed to invoke his Sixth Amendment right to self-representation.

"A right of self-representation at trial will not affirm the dignity of a defendant who lacks the mental capacity to conduct his defense without the assistance of counsel," Justice Stephen G. Breyer wrote for the majority.

The decision was among five passed on yesterday, implicating age discrimination, disability benefits and union organizing. The court still has to decide before the end of its term this month the constitutionality of the District of Columbia's handgun prohibition, punitory damages in the Exxon Valdez disaster and whether someone who rapes a child is subject to the death penalty.

The Indiana Supreme Court decision referred to the case of Ahmad Edwards who, in 1999, was caught shoplifting a pair of shoes at an Indianapolis department store. He shot and wounded a security guard and a bystander as he tried to escape. Edwards, who was diagnosed with schizophrenia and delusional disorders, was ultimately found capable to stand trial and asked to defend himself without the help or assistance of a lawyer.

At that time, the judge denied the accused’s request. Edwards was convicted of attempted murder and battery with a lethal weapon and given a sentence of 30 years in prison. Edwards appealed, based on the right to self-representation. After the Indiana Supreme Court ruled in his favor, the state appealed.

The High Court did not fully agree with Indiana. It refused the state’s request for a test that would disallow self-representation if the person cannot communicate coherently. Justice Stephen Breyer said judges should "take a realistic account of the particular defendant's mental capacities." Of the same opinion showed to be Chief Justice John Roberts and Justices John Paul Stevens, Anthony Kennedy, David Souter, Ruth Bader Ginsburg and Samuel Alito.

The only justices who disagreed are Antonin Scalia and Clarence Thomas, who pointed out that an individual who is competent to stand trial and voluntarily gives up a lawyer has a right to conduct his own defense.