SALT LAKE CITY — As family members mark the three-year anniversary of 15-year-old Anne Kasprzak's death Tuesday, a judge will be deliberating whether the 17-year-old boyfriend accused of killing her should stand trial as an adult or as a juvenile.

Final arguments were delivered Monday before 3rd District Juvenile Judge Dane Nolan over whether the defendant, who was 14 when he allegedly beat Kasprzak to death and dumped her body in the Jordan River, should be certified as an adult.

Prosecutors said the killing was extremely violent and if the boy stays in the juvenile system, the most he would serve is three years. The teen's attorney countered that prison is no place for a teenager while the juvenile system can immediately offer him help to rehabilitate.

Nolan already ordered the teen, whom the Deseret News has chosen not to name at this time, to stand trial on charges of murder and obstruction of justice. If he stands trial in juvenile court and is convicted, the teen would be released from state custody when he turns 21.

"This is an adult crime," argued prosecutor Patricia Cassell. "If there ever is a case that should be certified, it is this one."

Cassell said Kasprzak's life "is worth so much more than three years."

But defense attorney Bill Russell said his client was a typical immature teenager in 2012, does not have a criminal past and is not likely to reoffend.

The evidence for certifying the teen is "overwhelming," prosecutors said, noting the brutality of the crime combined with how well it was planned make it worthy of adult certification. Kasprzak's skull was cracked in three places and multiple bones in her face were fractured.

"This is the most aggressive and violent of crimes," Cassell said.

Even after her face had been smashed, the boyfriend continued his blows, she said. "At any point he could have stopped."

And then, after her body was beaten lifeless, Cassell said the defendant threw Kasprzak into the Jordan River. The teen originally lured Kasprzak to the Jordan River Parkway, she said, knowing it was an isolated area.

"This location was not an accident," Cassell said. "This was a willful and calculated act."

Cassell noted that the defendant was not educationally delayed, did not have a learning disability, and was in fact considered one of the smartest students in his grade school class. She further argued that if the juvenile is placed in the adult system, he will have services and treatment available to him possibly for the rest of his life. Plus, she argued that the juvenile system is not equipped to treat someone accused of such a brutal crime.

"There are certain crimes where the adult system has more experience," Cassell said, adding that the teen simply poses too much of a risk to the community to be released on the streets in just three years.

But Russell countered in his closing arguments that while the juvenile system would start providing quality services immediately, the Utah State Prison could offer only an "archaic" system of services for a juvenile. Prison would only teach him how to become a more hardened criminal with antisocial behavior, he said. The defendant would receive treatment in certain adult programs only when space becomes available. And he would not get the special attention to continue his education that he would receive in the juvenile system, Russell argued.

Russell noted that one of the doctors who evaluated the defendant, who was from the juvenile system, believes the teen is at low risk to reoffend.

The defense attorney didn't dispute that Kasprzak's death was brutal. But he said it was in no way was premeditated.

Russell also noted that the case would have been different — and his client would have received two more years of treatment during critical developmental years — if prosecutors hadn't waited so long to file charges against him. He said it isn't his client's fault that the state waited until he was 17 to file charges.

Cassell countered that prosecutors simply didn't have a strong case until 2014 when they met a former veteran police officer who now runs a company specializing in examining cellphone data.

Should Nolan decide to keep the obstruction charge in juvenile court and certify the teen as an adult to face the murder charge, Russell said there would be no need for two separate trials because his client would immediately plead guilty to the obstruction charge so he could begin rehabilitation.

Nolan took the case under advisement. He is expected to reconvene court when he has made his decision and will make an announcement from the bench. That decision could be one to two weeks away.

Email: preavy@deseretnews.com, Twitter: DNewsCrimeTeam