SOMERSET, Pa. -- With two dead bodies lying in ravines below Beam Rocks two months ago, state police believed they had a crime scene in Laurel Summit State Park.

"Personally," state police Lt. Brad Shields said in an interview March 31, "I find it hard to believe that two people fell off that cliff there by accident."

However, on a rocky path almost 40 feet above the spot where Christopher Cardy's remains were found, investigators discovered evidence to the contrary. That physical evidence, combined with toxicology reports from Mr. Cardy and companion Sara Baum that showed they both had substantial amounts of antihistamine in their systems, led police to conclude yesterday that their deaths were accidental.

Among the rocks above, police found a small pool of blood and a pair of broken eyeglasses that belonged to Ms. Baum. Blood droplets led to a spot at the edge of the path where it appeared someone had lost his or her footing.

Police also found a red sweatshirt, apparently used to wipe away blood from the injured Ms. Baum. Ms. Baum's body was found in a crevice 16 feet, 9 inches below the path.

Evidence also suggested someone, believed to have been Mr. Cardy, had made his way from the path to Ms. Baum.

Then, more signs of problem footing were found near her body. Police believe Mr. Cardy fell from there to his death in a ravine at the bottom of Beam Rocks.

Mr. Cardy, 25, of Ligonier Borough, and Ms. Baum, 24, of Greensburg, had gone to the park March 29 on a day trip. The two were close friends, having known each other since their teen years. They once dated and split up, but they remained close.

Ms. Baum, who previously had been married, had a son who is in the toddler age range, police said.

In the early evening of March 29, video surveillance at a nearby store showed the pair buying soft drinks, Trooper Scott Mackanick, the lead investigator on the case, said at a news conference yesterday at the state police barracks in Somerset.

In the video, Mr. Cardy was seen wearing the red sweatshirt that later was found at the top of the scene.

State police interviewed dozens of the couple's friends and witnesses who saw them park her car in the Beam Rocks lot and head toward the trails at about 5:30 p.m.

By 6 p.m., police learned days later, the eyeglasses, sweatshirt and blood evidence were discovered by a hiker. No report was made that day of the finding, but Trooper Mackanick and Cpl. Ed Thomas said the articles and timing pointed to the time of the accidental falls.

Mr. Cardy's mother, Coleen Cardy, had been told by her son that he and Ms. Baum were headed to the state park.

When he did not return home overnight, Mrs. Cardy became concerned. She drove to Beam Rocks the following morning. She found Ms. Baum's car in the parking lot, and he was reported missing shortly afterward, at 10:25 a.m. March 30.

An autopsy, done on both victims at Conemaugh Memorial Hospital, showed that both had ingested relatively large quantities of chlorpheniramine. It is a potent antihistamine, commonly found in cough syrup, and it causes drowsiness. The drug can be prescribed, and it is found in over-the-counter medications, police said.

Ms. Baum had four times the normal dosage in her system. Mr. Cardy had 30 times the normal dosage, police said.

In that state, police said, their bearings could have been affected by their use of the drug.

No alcohol was found in either of their remains, Trooper Mackanick said.

Some pills, containing the drug Coracidin, were found, but there was no evidence either of them had used them, the trooper said.

The autopsy showed Ms. Baum died of a fractured skull, likely caused by the fall into the crevice.

Mr. Cardy died of a broken neck.