Maine news, sports, weather from Portland Press Herald / Maine Sunday Telegram, Portland, Maine

September 25, 2012

DNA in 1980 Maine murder case shown to match defendant

Samples from the body of Rita St. Peter match the DNA profile of Jay Mercier, an expert says.

By DOUG HARLOW/Morning Sentinel

SKOWHEGAN — DNA samples taken from the body of Rita St. Peter in 1980 match the DNA profile of Jay Mercier of Industry, the man who is charged with sexually assaulting and killing her, a state witness said in court Monday.

"Unless you have an identical twin, there is no one else in the world with your DNA," Kathy MacMillan, a forensic DNA analyst with the state police crime lab, told the jury in Somerset County Superior Court.

MacMillan said the possibility that DNA samples taken from St. Peter's body didn't come from Mercier is one in a trillion.

MacMillan's testimony came on the third day of the murder trial for Mercier, who was 25 when St. Peter's body was found off Campground Road in Anson on July 5, 1980.

St. Peter, who was 20, was last seen alive around midnight on July 4, 1980, walking toward the bridge connecting Madison and Anson. She had been at a Fourth of July party and stopped at the Depot Tavern in Madison for a nightcap.

Two witnesses told the jury last week that they saw Mercier in his truck outside the bar around the same time. Mercier's defense team has said that because Mercier lived a few blocks from the bar, it would not be unusual for him to be seen in downtown Madison.

Skowhegan attorneys John Alsop and John Martin have told the jury that DNA evidence may prove that Mercier and St. Peter had sex, but won't prove that he killed her.

Prosecutors say Mercier, now 57, had sex with St. Peter, beat her with something like a tire iron, then ran her over with his truck.

The state's chief medical examiner testified Monday that St. Peter died from blows to the head and chest.

Dr. Margaret Greenwald said the autopsy report by Chief Medical Examiner Henry Ryan in 1980 showed that a long, heavy object was used to kill St. Peter.

Assistant Attorney General Andrew Benson and his co-counsel, Assistant Attorney General Laura Nomani, have presented evidence showing that tire prints taken from Mercier's truck the day the body was found match tire prints at the scene of the killing. Alsop has pointed out that several types of trucks could have had the same tires that year.

While Mercier was a suspect in St. Peter's death and the case remained open for 32 years, Benson said Maine State Police Detective Bryant Jacques struck "forensic gold" in 2005 when he took the butt of a cigarette Mercier had smoked and turned it over to the crime lab.

DNA testing on the cigarette butt matched samples taken from St. Peter, giving police probable cause to get a search warrant in 2011 for a swab from Mercier's mouth.

Investigators collected samples of fluid from St. Peter's body in 1980, but testing at the time could not produce DNA evidence. The samples were used as evidence Monday in court.

Mercier remains in the Somerset County Jail. He will face 25 years to life in prison if he is convicted. The trial continues Tuesday.

 

Morning Sentinel Staff Writer Doug Harlow can be contacted at 612-2367 or at:

dharlow@centralmaine.com

 

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