MOSCOW  The man suspected of murdering a prominent human rights lawyer and a journalist in January has admitted committing the crime, saying he did it out of “personal enmity” for one of the victims, his lawyer said Friday.

Investigators say that Nikita Tikhonov was the shooter and that an 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 a reporter, Anastasia Baburova, were leaving a news conference. Investigators say that Mr. Tikhonov ran up behind them and opened fire, instantly killing Mr. Markelov, 34. Ms. Baburova, a 25-year-old trainee reporter, was wounded and died later at the hospital.

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