MOSCOW — The man suspected of murdering a prominent human rights lawyer and a journalist last January has admitted to committing the crime, saying he did so out of "personal enmity" for one of the victims, his lawyer said Friday.

Investigators say that Nikita Tikhonov was the shooter, while his accomplice, Yevgenia Khasis, acted as lookout. Both have been identified as ultranationalists, and were arraigned in Moscow on Thursday.

The attack, which shook the beleaguered human rights community here, was carried out in broad daylight just blocks from the Kremlin as Stanislav Markelov, the lawyer, and Anastasia Baburova, a reporter, were leaving a press conference. Investigators say that Tikhonov ran up behind them and opened fire, instantly killing Markelov, 34. Baburova, a 25-year-old trainee reporter, was mortally wounded and died later at the hospital.

Tikhonov intended to kill only Markelov, his lawyer, Yevgeny V. Skripilyov, said on Echo Moskvy radio.

"He said that he committed the murder of the lawyer, Markelov," Skripilyov said. "There were no ideological differences, just personal enmity."

Skripilyov would not elaborate, though his remarks suggest that his client is the same Nikita Tikhonov named as a prime suspect in the 2006 murder of an anti-fascist campaigner. Markelov, who represented a surviving victim of that attack, is widely credited with securing serious prison sentences for the accessories to that murder.

Tikhonov, however, was never arrested in that case.

Skripilyov said Tikhonov told him that Ms. Baburova's death was an accident, seeming to clear up a longstanding question of whether the journalist, too, was a target.

"It was an unconscious act," Skripilyov said. "He found out later and did not know that she had been mortally wounded," he said, speaking of Tikhonov. "He says that he did not intend to cause her death and deprive her of life."

It is still unclear whether Tikhonov and Khasis acted alone, or in coordination with one of Russia's numerous nationalist groups.