Raad al-Jubbouri was a presenter on local television channel al-Rasheed and wrote editorials about institutional corruption for an Iraqi newspaper.
A photograph of the body seen by Reuters showed bruising to the face. Initial police reports said the injuries indicated Jubbouri had scuffled with his assailant before being shot in the heart late on Tuesday at his home in the western Qadisiya district.
The identity of the killer was not known.
The head of the Journalistic Freedoms Observatory and a person who knew Jubbouri said the presenter had been threatened several times before his death and gave them telephone numbers to call if anything should happen to him.
"He received letters threatening him a year ago," said the person who knew Jubbouri but declined to be identified. "I read two of them, they contained death threats and foul words".
Iraq has consistently ranked amongst the most dangerous places in the world for journalists, long-running civil conflict combining with political tensions in Baghdad.
The head of the Institute for War and Peace Reporting Ammar al-Shahbander was killed in a car bomb explosion in Baghdad over the weekend.
The Committee to Protect Journalists, a media advocacy group, says that at least 15 journalists have been killed in Iraq since the beginning of 2013.
(Reporting by Baghdad Bureau; editing by Ralph Boulton; Writing by Isabel Coles; editing by Ralph Boulton)