LYMAN — In 1978, the body of an 18-year-old Kennebunk High School senior was found in a hayfield in a remote area of Lyman.

Mary Ellen Tanner, a popular student who participated in the school band as a majorette, had died of blunt trauma. At one point, 25 detectives were assigned to the case, checking hundreds of tips. But no arrests were ever made.

Little has happened in the investigation in recent years – until last month.

In July, a police informant gave detectives a puzzling tip: Go check out the bed of an old rusty pickup truck parked at a farmhouse in Arundel.

Detectives found the pickup bed covered with leaves and debris. The owner of the truck – who is not a suspect – told police it had been there about 10 years.

Brian McDonough, a Maine State Police detective, said detectives took paint samples from the truck and will compare them with evidence collected 18 years ago.

Because the murder occurred so long ago, it’s uncertain whether modern crime tools such as DNA testing will provide crucial clues, McDonough said.

“We’re taking 18-year-old evidence and evaluating it by applying today’s techniques, ” said McDonough. Some old physical evidence will be re-examined, he said, along with the paint samples from the truck bed.

All of the evidence is being analyzed at the Maine State Police crime laboratory. It’s uncertain when the results will be available.

McDonough declined to provide specifics of either the significance of the paint on the truck or how the informant came to have information about it.

“We were told the truck was at this location and it would behoove us to look at it, ” McDonough said.

At the time of the slaying, investigators collected volumes of evidence, including scores of photographs taken at the site where Tanner’s body was found. It’s uncertain whether she was actually killed there.

Larry Labrador, who lives at the Arundel house where the truck bed was found, said his nephews bought the truck secondhand about 10 years ago. They removed the bed and left it in his yard.

Labrador said neither he nor his nephews ever knew Mary Ellen Tanner.

“The police asked me if they could have a look at it and I said `Go right ahead, ‘ ” Labrador said.

A LONG LINE OF LEADS

The latest tip in the Tanner case is one of hundreds that have been investigated in the mysterious death over the years.

State investigators followed leads, interviewing people in Maine and other states throughout the country.

Tanner was last seen alive about six miles from home by friends who dropped her off at Lower Village in Kennebunk. She told them she’d hitchhike home, but she never got there.

She’d planned to attend a funeral in Massachusetts that weekend, so when she didn’t return home, family members were not too concerned.

Neither her father, Charles Tanner, nor any other family members will now talk publicly about the girl’s death.

“It’s a painful memory for them, ” said McDonough, who continues to keep in contact with the Kennebunk family.

At the time of her death, the state medical examiner’s autopsy revealed that Tanner was three months pregnant and had died of “blunt trauma.” No weapon was ever found.

Tanner’s body was covered with cuts and bruises.

Her killer left her in the Lyman field partially clothed; her jeans were missing and her body was badly decomposed because of the intense summer heat.

At the time, the rural hayfield had been a sort of hangout for local teen-agers, who sometimes went there to party. On the night before Tanner was found, one such party occurred.

“She was found within a couple of hundred yards from where the party was. But it’s a pretty big area, you’d really have had to have been stumbling in the dark to have come upon her, ” said Michael Pulire, a detective with the state Attorney General’s Office who is working on the case with McDonough.

On a visit to the site last week, investigators carried a voluminous case file to help them pinpoint the exact site where she was found. It was not an easy task.

Now home to a herd of cattle and a couple of abandoned trailers, it is reached only by winding dirt roads that are miles away from the nearest two-lane asphalt thoroughfare – curvy, rural Route 35.

“Whoever did it has to have known where this place is, ” McDonough said. “It’s not the kind of place you just find by accident.”

BODY SPOTTED BY PILOT

Dan Alho was a 22-year-old pilot at the controls of a Cessna 180 when he spotted Tanner’s body in that summer of 1978, shortly after takeoff from a dirt runway.

“I remember I always used to look down and this time I happened to look down and saw her there lying in the grass, ” Alho recalled.

He said others in the plane speculated that the corpse was just a deer. But when they circled the plane and landed again, he said, there was no doubt that they’d found the victim of a brutal homicide.

For Alho, the images of that hot July day are not easy to shake. Interviews with police, someone running to get help, the bloated body of a young woman lying face down in thick green grass.

“You don’t realize how close to home something like this is until it happens. Then you realize this is not New York or whatever. It can happen anywhere, ” Alho said.

Police investigators are frustrated. Once a case gets nearly two decades old, it is increasingly harder to chase down new leads.

“We’re always hopeful that someone will remember something, somebody will have a tip and that we’ll get that stroke of luck, or that big break, ” McDonough said. “We just don’t know.”