Raleigh, N.C. — A federal judge has denied a motion seeking a new trial for an Army doctor convicted almost 30 years ago in the slayings of his wife and two daughters at Fort Bragg.

Senior U.S. District Judge James C. Fox issued his 47-page ruling Tuesday, saying Jeffrey MacDonald had failed to prove that new evidence he purported to have in the case would have convinced jurors to acquit him.

MacDonald was convicted in 1979 of the Feb. 17, 1970, murders of his pregnant wife, Collette, and their two daughters, Kimberly and Kristin. He has maintained his innocence, claiming a group of drug-crazed hippies broke into his home and attacked his family.

The case inspired two books, "Fatal Vision" and "Fatal Justice," and a television miniseries that carried the name of the first book.

Since his conviction, MacDonald has filed numerous appeals, arguing new evidence and prosecutorial misconduct should allow him to have a new trial.

In 2006, the Fourth U.S. Circuit Court of Appeals agreed to give the case another look after a retired U.S. marshal swore in an affidavit that  woman told him she was in MacDonald's Fort Bragg home on the night of the murders. The marshal also said he heard  the woman make the same claim to federal prosecutor Jim Blackburn and that Blackburn threatened to indict her for murder if she made the claim on the witness stand.

Blackburn has denied the allegations.

The retired marshal, Jim Britt, died last month.