Confessed hitman details killing of Palms waitress — VIDEO | Local Las Vegas

A homeless man who said he was paid to kill a Las Vegas firefighter's wife laid out in court Wednesday several plans for the slaying.

Noel "Greyhound" Stevens testified he did not believe it the first time George Tiaffay said he wanted Shauna Tiaffay dead, offering $1,000 for a hit.

But when the veteran firefighter of 10 years and graduate of the U.S. Military Academy at West Point upped the price to $5,000, Stevens said, he listened more closely.

The couple's relationship had been rocky since the fall of 2011, and by late 2012, they were separated and in the process of divorce. The firefighter thought his wife spent too much money, Stevens said.

"They were arguing," Stevens testified Wednesday at the firefighter's murder-for-hire trial in Clark County District Court.

Within weeks, Shauna Tiaffay was bludgeoned to death with a hammer.

Stevens testified that he was told he would get $100 per week for the job.

Stevens said he and George Tiaffay, with whom he had become friends in years prior, discussed hitting Shauna Tiaffay, a 46-year-old mother, over the head, placing her in her car and driving it into a wall to fake an accident. But an autopsy might reveal the first blow to her head and arouse suspicion.

They talked about wrapping a plastic bag over her head, but "I could get scratched," Stevens said. That would give investigators his DNA.

He said they considered killing her at the Palms, where she worked as a cocktail server. Stevens thought he would stab her. George Tiaffay drew up a map, showing where his wife parked her car, Stevens testified, but when he jumped the wall into the parking lot, he was startled by heavy police activity and took off.

Investigators have said they found store surveillance camera recordings of the two men buying a hammer, knife and gloves a few weeks before Shauna Tiaffay's death.

Stevens said the firefighter handed over a key to his wife's Summerlin home, and he scoped the place out about 20 times, at one point entering and stealing some of Shauna Tiaffay's jewelry and underwear.

Then one night in September 2012, Stevens waited in nearby bushes for her to arrive home, but he was scared when a light shone on him.

The firefighter told Stevens he and his wife were starting to reconcile.

The timing seemed ideal.

"It looks better for him," Stevens said, "if they're getting along."

Defense lawyer Robert Langford has asked jurors to question the validity of Stevens' testimony.

George Tiaffay and Stevens were linked by cellphone records that indicated the duo met a few hours after the killing, authorities have said.

Stevens, now 40, has pleaded guilty to six charges, including first-degree murder, robbery and two counts each of burglary and conspiracy. He is awaiting sentencing, and his testimony is expected to continue Thursday afternoon. The former firefighter, now 43, faces eight counts, including murder, robbery, burglary and conspiracy.

Early on the morning of Sept. 29, 2012, Stevens broke into Shauna Tiaffay's apartment and waited. He wore black gloves, a black beanie with holes cut out for his eyes, a black long-sleeve shirt, jeans and gym shoes. He collected some of her possessions, drank some vodka and waited in the bathroom.

Around 3:30 a.m., Stevens heard the car door slam. He grabbed his hammer and crept toward the door.

"Why are you doing this?" she said when she saw him.

He didn't answer.

She collapsed from the first blow to the head.

"I jump on top of her," Stevens said. "I keep on hitting her."

The wooden handle broke, so he clutched the metal and struck her with the claw.

"I hit her until she doesn't move anymore," he said.

He grabbed her bags, staging a robbery, and took his hammer.

"Who told you to make it look like a robbery?" prosecutor Marc DiGiacomo asked.

"George did."

Stevens walked out of the apartment and left the garage door open.

"That's the sign," Stevens said.