The Baseline Killer was violent and twisted - nine murders and eight rapes.
Mark Goudeau was also smart and strategic. He left few clues. But in one case, detectives said he got greedy, taking a crime scene trophy that would eventually crack their 13-month-long investigation.
"They needed someone," Goudeau said in an exclusive interview. "I was the perfect person. I lived in the neighborhood. 'Oh, he's black. Oh, he's an ex-con. We can use him. Ain't nobody going to believe him 'cause he's an ex-con.'"
Goudeau spoke from behind bars in the only television interview he'll ever do. Goudeau insists he was framed.
"There's nothing linking me to these crimes," Goudeau said. "Nothing. They couldn't place a gun in my hand. They couldn't place no damn bullet, or whatever, in my hand."
Indeed, detectives never found a gun. Instead the most powerful evidence used to link Goudeau to nine Baseline killings came from one crime scene.
It was Dec. 12, 2005 and preschool teacher Tina Washington had just left work and was going to catch the bus home. An hour later, she was found in a pool of her own blood. Among the spent bullet casings found at the scene was a "misfired" bullet that would prove to be a key to the case.
What was missing from the scene was a gold ring that Washington's children had given to her. Police purchased a copy of the ring and used it as a model when they searched pawn shops and continued their investigation.
Over the coming months, investigators examined the misfired bullet found at the Washington murder scene. The marks on the sides revealed a unique pattern that only the killer's gun would leave. Eventually, bullets from the nine Baseline murders all matched that pattern.
But investigators had little other physical evidence and no suspect yet.
"I don't understand how the absence of evidence is evidence," said Goudeau's wife, Wendy Carr.
"Listen, these are people that made a rush to charge," Carr said. "I think maybe they thought Mark was their guy and they would repeatedly come to our house."
After police arrested Goudeau in the rapes of two sisters, they executed three search warrants at his home over a month's time. Carr alleges those searches gave desperate detectives ample opportunity to pin the murders on her husband. During the last search, police found Washington's ring hidden inside a shoe.
"Supposedly they missed it all this time," said Carr. "And according to police it was in a baggie in a heel of shoe with the shoe protruding off the shelf. So obviously I don't know how they think that can be believable."
"How else could the ring get there?" Carr said. "And why is the ring void of Mark's DNA? And the victim's DNA is not even on that ring."
Carr's theory is that detectives planted the copy of Washington's ring in her home. She claims they never found the real ring.
But when the 5 Investigates team examined the evidence, they made a discovery that undermines her theory. 5 Investigates reporters found two rings – the one police purchased and the one police found in Goudeau's shoe.
5 Investigates reporter Tammy Leitner: "We looked through the evidence and saw the rings the detectives had purchased and then we saw the ring they found in your husband's shoe."
Wendy Carr: "OK."
5 Investigates reporter Tammy Leitner: "So there are two rings."
Wendy Carr: "Exactly. Well, the capability of them making a copy of the ring, anybody could have done that."
5 Investigates reporter Tammy Leitner: "You realize there will be some people that will say this sounds really far-fetched?"
Wendy Carr: "Well, you know, it happens. Cops are just people and these people were under enormous pressure to make an arrest."
"Phoenix police put that there," Goudeau said in the exclusive interview. "None of this was discovered until a month after I was arrested."
Investigators never did find the Baseline Killer's murder weapon - a .380-caliber pistol. But the gold ring found at Goudeau's home linked him to Washington's murder and the bullet found at the scene linked that murder to the eight others.
And that was enough for jurors to conclude he is, in fact, the Baseline Killer.
Copyright 2013 CBS 5 (KPHO Broadcasting Corporation). All rights reserved.