GREENSBURG, Pa. - The conviction Thursday of Greensburg teen Angela Marinucci for the slaying of Jennifer Daugherty has set the stage for the prosecution of five other suspects accused of kidnapping the mentally challenged woman, torturing her for more than two days, and stabbing and choking her.

Defense attorneys are arguing that two suspects are so intellectually deficient, they are ineligible for the death penalty.

On the other side is District Attorney John Peck, who will seek the death penalty against Ricky Smyrnes, 25, and Melvin Knight and Amber Meidinger, both 21.

Meidinger testified that Marinucci had wanted Daugherty dead, so Marinucci lured the victim to a Greensburg apartment shared by the suspects.

Marinucci ordered Smyrnes to get rid of Daugherty because Marinucci was jealous about Daugherty's relationship with Smyrnes, Marinucci's boyfriend, Meidinger, and jailhouse informants testified in a nine-day trial before Westmoreland County Judge Rita Hathaway.

The prosecution contends that Marinucci; Smyrnes; Meidinger; Knight; Peggy Miller, 28; and Robert Masters, 37, held Daugherty captive in the apartment.

They beat her, made fun of her, dumped spices on her head, forced her to drink mixtures of human waste and cleaning fluids, and tied her up with Christmas lights and garland, Meidinger testified. She said Smyrnes and Knight had stabbed and choked Daugherty, 30, of Mount Pleasant.

In about three months, Marinucci will be sentenced to life in prison without the possibility of parole for her conviction of first-degree murder. She was ineligible for the death penalty because she was 17 when Daugherty was killed.

Hathaway will hear testimony in July about the death-penalty issues raised by attorneys for Smyrnes and Meidinger.

Smyrnes contends he is ineligible for capital punishment because he has an IQ of 67 and functions at a third-grade level, according to defense petitions.

Meidinger's attorneys say her intellectual deficiencies render her ineligible for the death penalty under a 2002 decision in a Virginia case by the U.S. Supreme Court, which banned the execution of people with intellectual disabilities.

Knight's attorneys are challenging whether the death penalty is constitutional.

The Supreme Court has indicated that a person with an IQ of about 70 can be considered mentally retarded, rendering an offender ineligible for the death penalty.

"An IQ of 70 is often used to determine [a mental disability], but when someone is at a significant number above or below that, it's not a problem. In cases where they are close to that number, we can have a legitimate disagreement," said David Harris, a professor at the University of Pittsburgh School of Law.

Hathaway will hear testimony about the suspects' intelligence and weigh other evidence to determine if Peck can seek the death penalty.

No hearing has been scheduled on Knight's constitutional challenge to the death penalty. His attorneys might pursue a mental-infirmity defense, court records show.

Smyrnes' attorney, Mike DeRiso, and Knight's attorney, Jeffrey Miller, could not be reached for comment Friday.

Smyrnes and Knight will receive separate trials. Meidinger could be tried with either defendant or on her own. Trials dates will not be scheduled until September.

Meidinger's attorney, Amy Keim, said her client might seek a plea deal.

Keim and Peck said no deal had been offered for Meidinger's testimony.

"I feel it was the right thing for me to do," Meidinger told jurors. "I want to speak the truth to the family. I can't do nothing else."

Harris said Meidinger's testimony could become a factor in whether she served life in prison or was put to death.

Attorneys for Masters and Miller are trying to get plea bargains. Peck said they were less culpable than the four other suspects.

Peck said the conviction of Marinucci for first-, second- and third-degree murder in the slaying of Daugherty was substantiated by the evidence.

Prosecutors charged Marinucci and the five others in the 2010 torture slaying of Daugherty with all three murder counts, along with two counts of conspiracy and one count of kidnapping.

On Thursday, jurors found Marinucci guilty of all counts.

"It stands to reason that if you are guilty of first-degree murder and second-degree murder, you'd also be guilty of third-degree murder," Peck said Friday.

First-degree murder is a premeditated, intentional killing. Second-degree murder is a killing that occurs during the commission of another felony, such as kidnapping. In Pennsylvania, third-degree homicide is committed with wickedness and hardness of heart.