The longest, and most likely the last, of the German mass war crimes trials ended today with the handing down of a life prison sentence for one defendant, sentences of 12 years or fewer for seven others, and the acquittal of a ninth for lack of sufficient evidence.

Hermine Braunsteiner Ryan, 61, known to inmates of th Majdanek concentration camp as "the Mare" for the brutal kicks she was said to have given prisoners with her boots, received the life sentence. Ryan had been extradited to West Germany in 1973 from the United States. For 10 years before, she had lived in Helmuth, N.Y., with her husband, Russell, and American aircraft mechanic whom she had met and married in Austria in 1958.

The trial, which lasted five years and seven months -- one month less than the time it took to fight World War II in Europe -- chronicled in often harrowing testimony the brutalities committed by guards and officials of the S.S., Adolf Hitler's elite guard, at the Majdanek camp north of Lublin in what was then Nazi-occupied Poland.

While there was little dispute about the existence and horrors of the camp at which more than 200,000 Jews, Poles and Russians died between 1941 and 1944, the prosecution had difficulty finding reliable witnesses who could remember names and events clearly enough to pin specific murders on the defendants, a factor which in the view of experts here is likely to inhibit future large-scale prosecutions.

The West German office responsible for investigating Nazi crimes says that 87,305 cases have been started since the war. There have been 6,449 people sentenced; and 10 war crime trials are going on currently in West Germany, although none is the size of the Maidanek trial.

Stalling tactics by defense attorneys, and the absence of pressure for a quick hearing, from a generally uninterested public, contributed to the trial's dragging on past the previous record set by the original 1945-49 war crimes trial in Nueremberg.

Judge Guenter Gogen, 51, who has told reporters he was exhausted by the lenghty process, appeared to tremble as he read the ruling by a five-judge panel to a crowded room in Duesseldorf's state courthouse.

The defendants -- seven men and two women, all aged 60 or older -- stood for the sentencing, their backs to the courtroom, their bodies seemingly motionless.

Hildegard Laechert, 61, called "Bloody Brigitta" by the prisoners who remembered her, was given 12 years in prison.

The former deputy camp commandant, Hermann Hackmann, 67, received a 10-year jail sentence. The court gave eight years to Emil Laurich, 60, an S.S. corporal known as "the Angel of Death," and six years to Heinz Villain, 60.

Three of the former S.S. guards were sentenced on lesser counts of complicity to murder: Fritz Petrick, 68, a former sergeant, received four years; Arnold Strippel, 70, an ex-lieutenant, got 3 1/2 years; and Thomas Ellwanger, 63, a former corporal, was given a three-year term. Acquitted was Heinrich Groffmann, 60, an ex-sergeant.

The sentences, expected to be delayed by appeals, fell far short of what the prosecution had asked -- life jail terms for five of the defendants, jail terms of between 5 and 10 years for three of them, and acquittal of Groffmann. Defense lawyers, arguing that their clients had just been following orders and should themselves be pitied as victims of the Nazi system, had asked for acquittal in all nine cases.

The final verdict drew shouts of "scandal" and "insult for the victims" from some in the courtroom. Heinz Galinski, chairman of Berlin's Jewish community, also reacted angrily, saying the sentences "came nowhere even close" to atoning for the Majdanek atrocities. The court's judgement, he said, warranted "the sharpest protest of the Jewish community" as an insult to all Nazi victims.

Such legal proceedings tend to be seen in West Germany as a grim if necessary relic of the nation's increasingly distant Nazi past. In a public commitment to carry out that duty, the West German Parliament in 1979 decided to abolish the statute of limitations for Nazi murders.

The irony is that West Germany's integrity in pursuing Nazi criminals reawakens anti-German feeling abroad. The trials are sometimes seen here as designed to appease foreign opinion. Russell Ryan, whose wife was sentenced to life imprisonment today, told reporters: "American Jews demand these trials and this is what happens."

As the Majdanek trial showed, the difficulty West German prosecutors now run into when going after war criminals is the lack of surviving witnesses and the hazy memories of those who are still living. Suggesting his own displeasure at today's ruling, Judge Bogen said the result would have been different, and would have come more swiftly, had the case been brought 15 years earlier.

Precise testimony is important in a concentration camp murder case because under West German law, the accused must be linked to one or more specific murders that took place at the camp. Murder as a "crime of organization" -- that is, as a result of simply having worked on a camp's staff -- is not sufficient for a solid conviction.

In the Majdanek case, the court went to considerable length to find witnesses, hearing more than 300, including 200 former prisoners, most of whom now live in Israel, Poland, the United States and Canada. This sometimes meant traveling abroad to take testimony from former camp victims who, traumatized by their war experience, refused to come to West Germany.

The Picture of the Majdanek camp that emerged was gruesome. It was a row of stables where thousands of prisoners slept on straw in summer and shivered under paper bags in winter. There were six gas chambers, fed by carbon monoxide poisoning or zylon B, a mixture of cyanide and hydrogen, into which prisoners were led believing they were going to baths.

Epidemics and starvation killed many of those who were not beaten, drowned, shot or gassed to death. The Nazis abandoned the camp in the face of an advancing Soviet Army in July 1944, and it stands today as a memorial in Poland.

Of the 16 former Majdanek camp staff originally charged in 1975, one died, one was ruled unfit to stand trial, one was tried separately and four were acquitted in 1979 due to a lack of sufficient evidence against them.