BOSTON -- Former Massachusetts State Police administrator Bob Pino reflected back on some of the high-profile murder cases in Massachusetts that he helped solve during the course of his 23 years as a chemist at the Massachusetts State Police Crime Lab.

Case: Edward O'Brien, convicted of stabbing his best friend's mother, Janet Downing, to death on July 23, 1995

"I actually did the crime scene on that one where we had a trail of blood going through the house, going outside, going down the street.

That night, Eddie O'Brien went to the police station and then from there we actually took samples of blood from him, that were on him, which later turned out to be blood from the victim, on his legs, along with his blood. And then at the crime scene, we found two bloody fingerprints, one with his blood and one with his blood and the victim's blood.

We actually took the door and we took out a piece of the structure of the house because he had touched one of the pillars, we took the pillar out.

That's the way, that's kind of the way we would always work. We'd see the evidence and take the whole piece. I identified all the different stains, and packaged them DNA was done back then. We knew we had him right when it started because we kind of figured the story he was talking about was false, we were just working as they say to dot the I's and cross the T's in that case."

Case: Rod Matthews, convicted of beating his classmate Shaun Ouillette to death in 1986

"That was a homicide with Shaun Ouillette. I always remember that one because he had taken some other kids there to show them the crime scene, so then he denied it when we went to the house. He gave us baseball bats, and one of them was a wooden bat which was actually the murder weapon and he had hit him so hard that a piece of bone from the skull was embedded in the bat which later became part of the evidence.

There was a little stain, the bats actually looked like they were wiped, so there was just a little stain on them but then when you actually looked at the wooden bat, you noticed there was an indentation in it and that's when we found a little piece of bone in the actual bat. The identification of the bone was made by the medical examiner back then."

Case: Henry Meinholz Jr., convicted of raping and killing his 13 year old neighbor Melissa Benoit in 1990

"I was part of the collection in Meinholz. What ended up occurring was she was buried in his cellar, in Meinholz's cellar. And then we went to the crime scene and we found the body and we actually had to dig her out of the cellar, it was just a dirt floor cellar, we dug her out, she was covered with a little bit of coal and some other stuff, but she wasn't buried that far down.

And we just dug her right out and from there we found where the actual crime scene had occurred. She was killed in the garage, she was hung up in the garage by a ladder. There was blood throughout, he had tried to clean up but the blood had actually gone into the cracks, gone into, he had exposed 2 by 4's and the blood had actually sopped into the 2 by 4's. We could figure out back then that she was killed in the garage and taken back, taken into the cellar and buried."