The shooting death of a California author and his two children a month ago prompted a prompt ruling of suicide — and later questions about whether the initial finding was correct.

Authorities said Philip Marshall, in his mid-50s, killed his son Alex, 17, daughter, Macaila, 14, Jan. 31 at their home in Murphys before killing himself with his Glock. The three are shown in a family photo at left. The family dog also was shot.

Freelance investigative reporter and author Wayne Madsen, a colleague of mine in Washington, DC, travelled to the crime scene to probe the matter further. His reports have argued against the original finding of suicide. Local authorities responded late last week by saying their investigation is continuing.

One question raised by Madsen, shown at right, pertains to the logistics of the Marshall's shooting. In one column, Madsen reported: Exclusive: Investigative Author Phil Marshall right-handed but sheriff claims he shot himself in left side of his head. Madsen also questions why the local sheriff's office arranged for the victims' home to be cleaned so promptly. Sample news coverage is listed below in reverse chronological order.

As larger context, both Madsen and Marshall are authors writing about controversial topics. Marshall, a former United Airlines pilot, has written about his work with drug-runner Barry Seal during the Iran-contra scandal. Seal was murdered in 1986. Also, Marshall has challenged official accounts of 9/11. He was working on a new book about the 1963 assassination of President John Kennedy, one of more than 250 by various authors.

Madsen, a former Navy intelligence officer and NSA analyst, has written a half dozen books with hard-hitting commentaries. The most recent are L'Affaire Petraeus, published in December on the resignation of the CIA director. Madsen argues in it that Petraeus was caught being disloyal to the president in the re-election campaign. Madsen published The Manufactured President about the president's hidden past in June.

Madsen is a shoe-leather muckraker who seeks to emulate the late Jack Anderson. Madsen has travelled to Rwanda to investigate genocide, for instance, and to Southeast Asia to expose VIP Western pedophiles.

In the United States, his topics range from scandals at the highest levels of government to Peter Falk/Columbo-style street reporting to ferret out clues of deaths that catch his attention.