The son of a wife accusing her husband of attempted murder during a hike in Hawaii is expected to testify. This comes as new DNA evidence was unveiled for the jury during the attempted murder trial. NBC News’ Steve Patterson has the latest from the trial. 

HONOLULU (HawaiiNewsNow) – Jurors in the attempted murder trial of a Maui doctor accused of trying to kill his wife examined the alleged weapon Friday: a bloody rock.

Michelle Amorin, a criminalist from the Honolulu Police Department, testified about DNA testing on a bloody lava rock found at the crime scene last March.

Prosecutors say Gerhardt Konig repeatedly struck his wife, Arielle, on the Pali Puka Trail last year with that rock.

DNA analysis: What testing showed

DNA swabs of the alleged attempted murder weapon were taken from the blood-stained side and from the unstained side of the rock.

“From the stained area at the bottom, how many contributors were there?” asked deputy prosecutor Joel Garner. In DNA testing, contributors means the number of people whose DNA is detected in a sample.

“There was one, female,” said Amorin.

“And from the unstained area of the rock, how many contributors were there?” asked Garner.

“There were two,” said Amorin.

Defense challenges evidence

The prosecution says Gerhardt Konig hit his wife multiple times with a rock, but the defense says she started the scuffle and that he hit her in self defense.

“Obviously DNA cannot tell us how the blood got there, correct?” asked Gerhardt Konig’s attorney, Thomas Otake.

“That is correct,” said Amorin.

“DNA cannot tell us how an altercation may have started, correct?” asked Otake.

“Yes,” said Amorin.

“DNA cannot tell us who may have started an altercation, correct?” asked Otake.

“Yes,” said Amorin.

Additional evidence examined

Evidence was also taken from Gerhardt’s blood soaked T-shirt. A big blood stain came from a female while his shorts had no human DNA.

Gerhardt’s 19-year-old son, Arielle’s stepson, is expected to testify on Tuesday. The jury will hear if Gerhardt confessed to the crime or if it was a desperate suicidal call.