The fate of 56-year-old Jay Mercier will be in the hands of a jury Thursday.Mercier is accused of sexually assaulting and murdering 20-year-old Rita St. Peter and dumping her body on a desolate road in North Anson more than three decades ago.The prosecution rested its case around 10:00 Wednesday morning after calling their final witness, Detective Adam Kelley. Kelley was one of the investigators who questioned Mercier.The defense called six witnesses, who offered no new testimony, only corroborating earlier testimony that Rita St. Peter was drunk the night she was killed, July 4, 1980. Ruth Perkins of Skowhegan was in the same bar as St. Peter that night and described her as “very drunk. Her speech, her mobility, just her mobility in general.” The defense rested its case shortly before noon.The defendant, Jay Mercier did not testify at trial.Defense Attorney John Alsop did ask Judge John Nivison for an acquittal, which is standard practice in a murder trial. Alsop argued that the prosecution had not proven beyond a reasonable doubt that Mercier killed St. Peter. “It is a circumstantial evidence case your honor,” Alsop argued. “How have they ruled out alternative possibilities in this case?” Alsop pointed to 32 year old photos of tire impressions left at the scene of the crime. “In order for the jury to convict Mr Mercier in this case they have to be certain beyond a reasonable doubt that these are Jay Mercier’s tire tracks.”The defense team of Alsop and John Martin have maintained that the only thing the prosecution has proven is that Jay Mercier had sex with Rita St. Peter and lied about even knowing her to investigators for the past 32 years. “Can a jury convict someone of murder based on his denial of sexual activity? Does denial of sexual activity equal murder? The court should not be satisfied,” Alsop said to the judge. Deputy Attorney General Andrew Benson disagreed with Alsop’s characterization of the prosecution’s case. Benson told Judge Nivison they had proven their case and presented sufficient evidence that the tire impressions left at the scene were made by Mercier’s truck. “Common sense shows that Jay did cause the death of Rita St. Peter, either intentionally or knowingly or with a depraved indifference to human life.”In the end Judge Nivison decided to leave Mercier’s fate in the hands of the jury.Over the 5 days of the trial, the prosecution has argued that modern forensics were able to tie DNA taken from the victim’s body to Jay Mercier and match tire impressions taken from the body dump site to the truck Mercier was driving in 1980.The defense contends that the DNA evidence only proves Mercier had sex with Rita St. Peter and lied about it, but that this does not prove murder.Closing arguments are scheduled for Thursday morning.The jury should have the case by early afternoon.