Marks on accused found to match victim's tooth, fingernail

Digital images of a tooth and fingernail of an 82-year-old woman murdered in her Msida house matched the images of wounds on the right arm of the man standing trial for her murder, a computer expert yesterday told jurors.

"I was appointed by the inquiring magistrate to conduct an image comparative analysis by comparing several digital images with digital images of marks on Mario Pollacco's right arm," Martin Bajada testified.

"These comparisons showed that the digital image of one of Rose Mary Schembri's teeth matched a mark on Pollacco's arm. An image of the victim's right fingernail matched another mark on Pollacco's right arm. These were the only two perfect matches," he said.

Bajada was testifying before Mr Justice Joseph Galea Debono in the trial by jury of Pollacco, 38, of Msida, who is pleading not guilty to Schembri's wilful homicide in her house on June 3, 1998.

He is also accused of the theft of over Lm1,000 worth of cash and precious objects, qualified with violence.

Bajada explained how he took digital scans of casts of Schembri's teeth and fingernails. He also scanned casts of the teeth and claws of Pollacco's dog (since Pollacco claimed that his dog had caused the marks on his hand) and of marks on the accused's right arm.

He then conducted an image comparative analysis, superimposing each image on the images of the 14 marks on Pollacco's arm. Bajada explained that when two superimposed images locked into each other the computer signaled that there was a match.

Out of the 55 possible individual things, including teeth and fingernails, that might have caused any of the 14 marks found on Pollacco's arm, only two locked perfectly and one partially. The two perfect matches, Bajada explained, were of Schembri's tooth and fingernail.

He said that as long as the cast, on which he based his digital scans, was a perfect reproduction of the original object, then the digital comparison was reliable.

But, the expert said, his work should not suffice to carry the weight of the accused's guilt since his role merely consisted in comparing digital images. The testimony of the dental expert would eventually give the necessary weight to his conclusions, he added.

Earlier, clinical forensic expert Dr Mario Scerri said he had been appointed by the inquiring magistrate to examine Schembri's corpse on the scene of the crime and to examine marks on Pollacco's body.

In his testimony Dr Scerri gave a detailed power-point presentation of the report he compiled after conducting the examinations.

He arrived on the scene on June 4, 1998 at about 11 a.m. where he saw Schembri lying face-up on the floor in the hallway of her house. The room was in a disturbed state. This, combined with her body's position, led him to believe that the scene was a suspicious one.

The base of a white, broken statue of Our Lady was standing on the right of Schembri's head and the top part of the statue was lying near her out-stretched right arm. A small piece of the statue was seen on her left.

There was a sizable abrasion on her forehead and three distinct lacerations could be seen in the same area. These lacerations matched the points of a broken piece of statue.

Schembri had two lacerations on the back lower part of her head while her skull, beneath, was fractured. She had several other abrasions and bruises on her face and neck area.

Dr Scerri said that when he noticed that one of her teeth was moving he recommended that a cast of her teeth be taken for future comparison.

On June 6, 1998, Dr Scerri examined marks on Pollacco's neck, arms and hands. Pollacco told the expert that marks on his right hand had been caused by his dog three months ago.

He said that after dental expert Hector Galea compared these marks with the cast of the victim's teeth, he informed him that they matched.

"From my study I concluded that abrasions on the victim's neck were compatible with someone grabbing her from the back with a right hand and other marks on her neck were compatible with strangulation marks. The wounds indicate that Lucy (Rose Mary) Schembri was first beaten then strangled," the expert said.

"The wounds led me to believe that there was struggle, prior to the woman's death, during which she used her natural weapons. The state in which her body was found suggested that she had been dead for about 12 hours, which means that she died on June 3, 1998, at about midday," he said.

"Examinations of the marks found on Pollacco's arms suggested that they had been caused three or four days before he was examined on June 6, 1998. These marks were definitely not caused three months before. An abrasion on his right arm seemed to be a human bite mark and not that of a dog."

Under cross-examination, he said that he could not exclude the presence of more that one aggressor at the time of the commission if the crime. But, he explained, he had only been asked to examine Pollacco whom he had linked with the victim.

"A bite mark is like a key-hole," Dr Scerri explained, "It either fits or it doesn't. There are no two ways about it."

Pathologist Dr Bridgette Ellul followed Dr Scerri to the witness stand and explained that she had conducted an autopsy on Schembri's body on June 6, 1998. Schembri died as a result of "manual strangulation complemented with a blunt force trauma to the head," she testified.

The autopsy showed that a strong force applied on the neck had caused breakage and internal hemorrhage in the area, possibly also causing the fracture of several upper ribs.

The fracture of the skull was compatible with a fall and Dr Ellul explained that she believed that Schembri had been strangled while she was standing up and that, as a result, she fell backwards and fractured her skull.

Dr Ellul said that the autopsy showed that, other than the injuries she suffered during the assault, Schembri was a healthy woman for her age.

The trial continues this morning.

Dr Michael Sciriha, Dr John Attard Montalto and Dr Philip Galea Farrugia are appearing for Pollacco.

Seniour Counsel to the Republic, Dr Mark Said, is prosecuting.