CARIBOU – Multiple trauma, including strangulation and a heart injury, killed Erin Sperrey, 20, a fast-food restaurant employee who supervised the man charged with her murder, a medical examiner testified Monday.

The state alleges that Christopher Shumway, 20, beat Sperrey, then waited on customers Jan. 2, 2005, as she died of her injuries in the restroom of the Caribou Tim Hortons restaurant.

Opening arguments and testimony were heard in the jury-waived trial Monday in Aroostook County Superior Court.

Shumway has been charged with her murder, gross sexual assault, and the robbery of more than $1,200 from the restaurant.

Shumway has pleaded not guilty and not criminally responsible by reason of insanity. The trial is being conducted by Justice E. Allen Hunter and is expected to last three or four days.

Dr. Michael Ferenc, the state’s deputy chief medical examiner at the time of Sperrey’s death, said Sperrey’s face was bloodied and had boot marks across it. He said she was beaten on the chest, head, neck and upper back.

He said she had internal muscle bruising of the neck and throat and hemorrhages about the eyes and neck, and that the sac around her heart was filled with spilled blood from a heart injury. The injury was described as a ruptured auricle on the right side of the heart. As pressure increased from the bleeding in the sac surrounding the heart, the organ stopped pumping.

He said the beating involved multiple blows, but he could not count the injuries she suffered.

Several items of clothing Sperrey had been wearing were partially removed and torn.

“The facial injuries were nonlife-threatening,” Ferenc testified under cross-examination. “The compression of the neck area was caused by manual strangulation.

“The heart injury would cause death within a matter of minutes,” he testified. “It would be two minutes to half an hour.”

Crime lab experts testified that they found blood on Shumway’s clothes and footwear and that the blood belonged to Sperrey. Blood found throughout the restaurant was found to be Sperrey’s. Semen swabbed off Sperrey’s body was said to be consistent with Shumway’s.

A low sperm count made it impossible to determine a verified DNA match.

Shumway, the state alleges, was enamored of Sperrey, who had spurned his advances several times. It also is alleged that he wanted money to return to Massachusetts, where he was raised.

Prosecutors Andrew Benson and Melissa O’Dea are looking to prove that Shumway wanted to steal money from Tim Hortons and that Sperrey stood in his way.

They allege that Shumway raped Sperrey, placed her on the floor in the back of her own car, then drove south until he drove off Interstate 95 late on the evening of Jan. 2, 2005.

State police found the car in the median of I-95 at mile marker 231, southbound. Sperrey’s body was found on the floor of the car between the front and back seats.

Shumway is alleged to have hitchhiked a ride to Bangor with a passing motorist. He was arrested at a Bangor motel early on Jan. 3.

Benson told the court in his 40-minute opening statement that although Shumway may have been psychotic, dealing with mental disease for years, he was not criminally insane at the time he is alleged to have killed his co-worker.

Benson told the court that Shumway went to considerable trouble to cover up the crime before he was arrested.

Defense attorney Brad Macdonald of Bangor said the state has oversimplified the case.

“They seriously misjudged this complex situation,” he said during the lunch break Monday. “This case involves larger legal issues than the apparent factual issue.

“My client has no recollection of the incident,” he said. “He’s a man who has lived a long life of abuse.”

Macdonald questioned few witnesses Monday, except for the medical examiner and experts on blood and bodily fluids.

Ten of some expected 30 state witnesses testified Monday. They included Laura Cyr, who found the restaurant abandoned shortly before 8 p.m. Jan. 2, 2005; police officers who found bloodstains and other evidence in the shop; and the state trooper who discovered Sperrey in the disabled car just before midnight Jan. 2.

Caribou police Officer Douglas Bell reported finding spots of blood in the serving area of the restaurant, in a hallway and in the employee restroom. He also found footprints leading to where Sperrey’s car was parked and one set of tire marks leaving the area on the snowy evening.

Maine State Police Detective Darrell Pelletier testified that he was told two employees were working that evening, Sperrey and Shumway, and that more than $1,200 in cash was missing.

State police Detective Joshua Haines testified that blood splatters were found, especially in the restroom area. He said blood in the hallway to a door leading to the parking lot had footprints, a smearing pattern that looked as if something was dragged through the area.

State police Trooper Brian Meserve found the disabled car and Sperrey’s body.

A large amount of cash, nearly $1,100, was found in the disabled car.

Prosecutors on Monday presented nearly 50 items accepted into evidence. The items included photographs of the scene and of Sperrey, detailed drawings of the shop, currency, a video of the doughnut shop, two earrings found at the scene, a contact lens, clothing from both Sperrey and Shumway, and currency found in the car.