Baburova was walking with Stanislav Markelov, a lawyer for the family of a Chechen woman murdered in 2000 by Russian army colonel Yury Budanov, when an unknown assailant approached them from behind and shot the lawyer in the back of the head using a gun with a silencer. The gunman then shot the journalist, who was seriously injured and hospitalized.
"There are two versions [of what happened] - the first is that she was killed while trying to stop the killer, the second is that she was shot on purpose," editor Sergei Sokolov said, adding that the facts would only become clear after further investigation.
Baburova underwent surgery and was placed in intensive care, under police guard but died after 8 p.m. Moscow time (17:00 GMT).
Baburova, born in 1983, became a stringer with Novaya Gazeta last October and specialized in covering informal youth movements, including neo-Nazi groups.