Huseynov was shot several times while walking up the stairwell of his building on his way home from work, according to local press reports. The shooting occurred at approximately 9:00 p.m., and the editor died at the scene, the Baku-based independent news agency Turan reported.
The attack appears to have well planned and orchestrated. Chingiz Sultansoy, deputy director of the Baku Press Club, told CPJ in a telephone interview from the crime scene that a light at the entrance of the apartment building was not working, and that several telephones in the area had been disconnected at the time of the shooting.
Sultansoy told CPJ that Huseynov's family said the editor had received several threats and was concerned about his security.
Eynulla Fatullayev, an investigative reporter with Monitor, told CPJ he believes that Huseynov's murder was related to his work.
"We are shocked and saddened by the murder of Elmar Huseynov, and our thoughts are with his family and colleagues," CPJ Executive Director Ann Cooper said. "Press freedom conditions have declined in the last two years since President Ilham Aliyev took office, and we call on him to ensure that this case is aggressively investigated and prosecuted."
Monitor has long angered officials with hard-hitting commentary.
The magazine currently faces several lawsuits in retaliation for its critical reporting, and journalists working for the publication have faced a steady stream of harassment from government officials.
In February, military officials abducted Monitor journalist Akrep Hasanov and held him for five hours after he had exposed abuses and mismanagement in an Azerbaijani military unit.
Huseynov's murder comes amid a broad government crackdown on the media and opposition activists that followed flawed presidential elections held in October 2003.
Rauf Arifoglu, editor-in-chief of the opposition newspaper Yeni Musavat and deputy head of the Musavat opposition party, was arrested after the election.
In October 2004, Arifoglu was sentenced to five years in prison on charges of organizing antigovernment protests.