The 15th and final alternate juror was chosen Monday morning to hear the murder trial of Shane Sloan, and the case got under way with opening arguments and expert testimony from the doctor who performed the autopsy on the victim, Sloan's mother.

Sloan, 29, faces first- and third-degree murder charges for allegedly strangling Susan LaRue Feegler the morning of Feb. 5, 2001, in the Pine Township trailer they shared.

"This is a case about a suicide that resulted in a homicide," Christopher St. John, one of two defense attorneys representing Sloan, said during his opening statement.

Assistant District Attorney Samuel Zuck, who is prosecuting the case along with fellow Assistant DA David Ristvey, said Sloan maliciously killed his mother and "acted with a specific intent."

For Sloan to be convicted on the first-degree murder charge, which carries a life sentence with no chance of parole, the prosecution needs to prove he intended to kill his mother. The plan could have been formulated in an instant, Zuck said.

St. John painted a grim picture of Sloan's life, a downward spiral that in recent years had been marked by his "tremendously strange behavior" and failed suicide attempts.

Sloan claimed to be sexually abused as a boy while living with his father after his parents divorced, St. John said. After moving in with his mother, Sloan never fit in, St. John said.

During his teen-age years, Sloan often missed school because of Crohn's disease -- which took 3 feet of his intestines -- and he first began to think about committing suicide, St. John said.

The strange behavior began in recent years. St. John said Sloan often got around by walking backwards, sat alone in his trailer screaming, flicked a deck light at the trailer on and off repeatedly and sometimes marched back and forth on the deck, his attorney said.

Sloan became fixated on the theme of red horses in the biblical Book of Revelations, and then on communism or Red China, believing the Chinese would take over and enslave the world for 1,000 years, leading to the end of humanity, St. John said.

Sloan first tried to kill himself in October 2000, but state police -- who were called by his mother -- got him to drop a knife at his neck, St. John said. He was committed to the psychiatric ward of Sharon Regional Health System for eight days and put on lithium for diagnosed bipolar disorder. A drug test performed on Sloan after the slaying showed "no therapeutic amounts of lithium" in his system, St. John said. There was another failed suicide attempt the month before Feegler was killed, this time with Sloan sticking his head in a toilet bowl filled with ammonia and bleach, St. John said.

Sloan tried to kill himself four times on the morning of the alleged murder.

"He stayed up all night to kill himself so he would be dead before the morning, when he was supposed to report to Mercer County Jail," St. John said.

After his mother intervened during the second attempt -- with him cutting his arms and wrists with an Exacto knife -- Sloan "tried to knock out his mother but couldn't.

"He loved her and would change everything if he could. He saw himself as her burden," St. John said.

Dr. Karl Williams, a forensic pathologist at Ellwood City Hospital who performed the autopsy on Ms. Feegler, said she had four broken ribs and suffered several blows to the head and face, but died of "ligature strangulation." The ligature, in this case, was a towel, he said. The towel cut the flow of air and blood to the brain, he said.

Sloan kept his head down and several loved ones in the courtroom sobbed throughout much of Williams' review of five color photographs of Ms. Feegler from the autopsy. The defense unsuccessfully objected to the photos.

The prosecution was expected to call its second witness -- Grace Fales, grandmother of Sloan and mother of Ms. Feegler -- to the stand today. The case is expected to continue through the end of this week and possibly into the next.