He is accused of murdering 16 year-old Joyce McLain outside of Schenck High School in 1980 while she was out for a jog.
Three members of the Maine State Crime Lab taking the stand Monday to discuss what concrete evidence was found at the scene.
The first witness was Alison Gingras, a forensic chemist with the crime lab.
She spent several hours of the morning and early afternoon explaining her findings, as photos of Joyce's clothes the day she was murdered were projected on a large screen.
She discussed blood stains and tears on Joyce's shoes and socks, bra and underwear, and shorts and top at the time of the murder.
She also discussed swabs and smears taken from Joyce's body.
But, she says, through all the DNA testing, no evidence of semen or seminal fluid was found.
In fact, a later witness, Jennifer Sabean, a forensic DNA analyst with the crime lab, said of all the DNA testing done on Joyce's clothes, body, and alleged murder weapon, all results turned back insufficient evidence, meaning they were not able to detect enough DNA to complete a profile.
The only conclusive evidence returned was the DNA of Joyce herself.
Testimony will continue Tuesday morning in the Penobscot County Judicial Center.