Daniel Tavares Jr., center, is led away after pleading guilty in Pierce County Superior Court Friday, Feb. 15, 2008, in Tacoma, Wash., to the killing of a young Graham couple.

The evidence was no bigger than a postage stamp, but it was enough to catch a killer.

Daniel Tavares is in prison for the rest of his life for murdering Brian and Beverly Mauck in November in a dispute over $50. Detectives used two pieces of evidence found at the crime scene to convince him to confess to the murders.

When Daniel Tavares pleaded guilty to killing a newlywed couple in Graham, he knew investigators had him. He'd known it since a recorded interview with Det. Sgt. Ben Benson the day after the murders.

Detective: "We know a lot of what you've told us is lies. We've got evidence to arrest you for the murders of Brian and Beverly.

Tavares:"What??"

Benson, the lead investigator, gave KOMO 4 News an exclusive look at the same evidence he then showed Tavares.

Detective: "I'm going to show you something. I'm going to show you a couple things." 

Tavares: ----

Detective :"This is your fingerprint. In blood. These are the patterns on your shoes that you have on your feet right now."

The two crucial prints would have been easy to miss at the crime scene. Tavares had erased his shoe marks then covered the blood trail in blankets.

But just once, he stepped on a blanket and left a solitary print.

"We'd been at the crime scene for two days looking at this. It was imprinted on everybody's mind, what that pattern was," said Benson.

When Tavares came to the sheriff's office for an interview, he was still wearing the same shoes.

"He walked through some water in the parking lot and then onto dry pavement, and he left a shoe pattern on the pavement," said Benson.

A detective recognized the print and grabbed a picture of it before it dried.

But the key evidence was in what they first thought was a fingerprint. It didn't match Tavares' prints. But detectives soon realized it was a postage stamp-sized imprint from his palm.

"The palm print that we had, as soon as we had his match to the palm print that was in the blood, that's evidence that's hard to dispute. That puts him there with his hands in their blood," said Benson.

The Maucks' murder case got national attention as Tavares was on the run after assaulting prison guards in Massachusetts.

The case also prompted a report by Massachusetts state officials, which said Tavares should have been held behind bars for almost a year longer, but the administration of then-Gov. Mitt Romney failed to file paperwork in time to take away his "good time" credits.

Benson said that part of the story didn't matter so much here; his satisfaction comes from solving the crime and bringing a sense of closure for the young victims' families.