MACHIAS, Maine (AP) _ A 46-year-old man convicted of a double slaying recorded by the victims' videocamera was sentenced today to spend the rest of his life in prison.

Richard B. Uffelman of Machiasport was sentenced to life in prison for the shooting death of Florence Phillips and, concurrently, 50 years for killing her husband, Michael, on Aug. 29, 1989. Uffelman's attorney said it is likely he will appeal.

The slayings were recorded by a videocamera the Phillipses had set up in their kitchen to record alleged acts of harassment by Uffelman in a feud between the neighbors.

''We don't need a videotape to be legitimately horrified,'' Assistant Attorney General Jeffrey Hjelm said this morning in Washington County Superior Court. ''His conduct that afternoon was completely unjustified.''

Uffelman spoke for about 45 minutes in his own behalf, reiterating his past contentions that he had acted in self-defense.

''It was all in a father's defense of his family,'' Uffelman told Justice Robert Browne. ''I was set up to be murdered in a bizarre video game.''

He said that on the day of the killing he thought the Phillipses had fired at him. ''I even thought I saw smoke. That's the only thing that would make me shoot out of the living room window,'' Uffelman said.

''I did not want to shoot these people. We've lost everything,'' he added.

Uffelman's attorney, Kevin Wall of Camden, N.J., urged the judge to take into account his client's mental condition when sentencing him.

''I suggest that this was an ongoing mental problem that culminated at this time,'' Wall said. ''He went over the edge. He continues to hold fast to the belief he was defending himself and his family.''

But Browne followed Hjelm's sentencing recommendation. ''This tragedy should never have happened. Whatever the provocation was, it did not justify your response,'' he told Uffelman.

A Superior Court jury found Uffelman guilty and criminally responsible in October for shooting the Phillipses.

The videotape played during the trial showed the Phillipses leaving their house for a walk on the evening the crime was committed.

Following a nearly silent, 10-minute period, 20 to 25 shots rang out, blanketing the front of Uffelman's large, stately house with smoke. After a few minutes, Uffelman, carrying a rifle, was seen leaving the house and heading toward the road.

Three more shots were heard before Uffelman returned to the house with the rifle. A few minutes later, Uffelman and his two sons, ages 10 and 12 at the time, walked from the house toward the road, each carrying rifles. One more shot was heard, and Uffelman and his sons returned to the house.

Then, the tape shows the arrival of several state and county police officers.