Or that’s what they thought on Feb. 25, when the judge announced that a victim in the case was sick and the trial would have to wait until he could make a statement.

February turned into March and then April  three feet of crusty snow melted into a slushy deluge  and the 12 of them would remain in the jury room, playing cards or working crossword puzzles, on the days when they were called to appear. First they felt like uninvited guests and then, said Ms. Vasilyeva, like “spiders in a jar.” The delays made them angry, and in some cases, suspicious.

By May it was a test of endurance. Juror No. 4 kept complaining that she was needed in her hometown in Siberia, where her mother was sick. The juror was so reluctant to break the quorum that she twice bought airplane tickets and returned them, Ms. Vasilyeva said. Though they were still split on the question of guilt, all 12 felt a stubborn desire to finish, she said.

“I said to everybody, ‘Let’s go through to the verdict. I’m happy to sit here all night,’” she said.

She was not the only person in suspense. Sergei Antonov, the defense attorney, had felt confident since the fall, when he watched jurors smirking at prosecution witnesses. Then, one of the investigators assigned to the case had approached him in the smoking room and congratulated him on winning, he said.

“He said, ‘We listen to the jury and we know they are tending toward acquittal,’ ” he said.

But as the recess dragged on, Mr. Antonov realized that one of 12 jurors was bound to drop out.

“When nothing is happening, sooner or later the question arises, ‘Does it make sense to show up tomorrow?’ ” he said. “These people, for three months, they came every day. I realized that they wanted to give a verdict.”