A Salt Lake youth charged with killing a father and his son during a fight last June said he "likely" stabbed the father but could not have stabbed the son because he never saw him.

Fred Alvarez, 17, told a 3rd District Court jury he began swinging a knife around after Don Newingham, 39, stabbed him in the leg during a fight in a Rose Park neighborhood on June 9.Moments before the fight, Alvarez refused to let Newingham into a party that was being held at 467 N. Morton Drive. Witnesses said words were exchanged and a fight began in the front yard. Alvarez said Newingham stabbed him first.

"This dude came running at me. I stuck my leg out and he stabbed me in the leg," said Alvarez. "I pulled it out after I got stabbed."

Alvarez said he began swinging and "punching" with the knife "trying to keep (Newingham) away."

"I probably did stab him. I didn't say I killed him."

Alvarez is charged with two counts of capital homicide for the stabbing deaths of Don Newingham and his 18-year-old son, Shane, who prosecutors say tried to protect his father. Both died from stab wounds they received during the fight. Alvarez could face the death penalty if the jury decides that he killed both victims.

Deputy County Attorney Kent Morgan questioned Alvarez's story and queried him about each specific stab wound Don Newingham received.

Morgan referred to testimony from the chief medical examiner, who said one of the wounds on Don Newingham showed that the knife had been withdrawn, turned and then reinserted into the same wound.

"By swinging, you wouldn't have inserted the knife in the same spot twice, could you?"

"I guess not," replied Alvarez.

Referring to two other stab wounds Don Newingham received, Alvarez said, "By the way I was swinging the knife, those two were possibly the ones I could have done, but I'm not sure."

Witnesses for the defense testified Monday that they heard Tony DeHerrera claim responsibility for stabbing one of the victims. Others also testified seeing DeHerrera walk into the house after the stabbing with bloody knives.

But Alvarez said he didn't see anyone with knives after the fight and never heard DeHerrera make any statements about stabbing anyone.

Morgan asked Alvarez about previous testimony from Paul Velasquez, who said he saw him stab both Don and Shane Newingham.

"He's lying because I didn't even see Shane there," Alvarez said.

"But you did have his blood on your shoes."

"I don't know how that got on there," he replied.

Morgan said Alvarez's entire testimony depends on whether or not he stabbed himself in the leg or was stabbed first by Don Newingham. "If you stabbed yourself in the leg then you were not acting in self defense, were you?" Morgan asked.

"I didn't stab myself in the leg and I don't have any reason to lie," he responded.

The jury was to begin deliberations Wednesday afternoon.