GREENVILLE — Two people were charged Thursday morning with murdering a Greene Township man and seriously injuring his daughter in her Greenville apartment early Tuesday.

Ronald Victor Machado, 21, of Jamestown, and Krystle S. Weaver, 20, of Fowler, Ohio, are charged with homicide, attempted homicide, conspiracy to commit homicide and burglary, Mercer County District Attorney Robert G. Kochems said at the office of District Judge William L. Fagley, Greenville.

Machado told police he and Ms. Weaver attacked Thomas Lorigan, 44, of 183 Ray Road, and Heather Turk, 22, of 94 Clinton St., Apartment 103, with two knives when the father and daughter returned from the store, according to court documents.

“We believe it happened almost instantaneously,” Kochems said of the attack.

Ms. Weaver and Machado had previously lived with Ms. Turk in the apartment and authorities are still looking into possible motives for the crime, which may include Machado and Ms. Turk being involved with each other, he said.

Machado and Ms. Weaver were served arrest warrants Thursday afternoon and are being held in Trumbull County Jail, said Dennis Stephens, chief of Greenville-West Salem Township police.

Machado was already being held in Trumbull County Jail on a parole detainer, Kochems said, adding he didn’t know why Machado is on parole. Fagley’s office staff said they believe he’s on parole from an incident in California.

Ms. Weaver and Machado are expected to be extradited to Mercer County in about a week for arraignment, Kochems said.

Ms. Turk, who’s married but separated from her husband, had her two children, who are about 1 and 2 years old, with her when she was attacked. They were taken by Mercer County Children and Youth Services and are in protective custody, Kochems said.

He wouldn’t say where Ms. Turk is hospitalized but said she remains in stable but critical condition.

According to the affidavit of probable cause:

Police were called at 12:43 a.m. to a domestic disturbance at 94 Clinton St., Apartment 103. The 911 dispatcher said they lost the caller but heard someone screaming.

At 12:46 a.m., police found the body of a white man, later identified as Lorigan, inside the apartment. He had been stabbed repeatedly and died from the wounds.

Police also found a white woman, now known as Ms. Turk, on the kitchen floor. She had also been stabbed repeatedly in the rear part of her skull and brain and was still alive but unresponsive.

Police learned that Machado and Ms. Weaver had been staying in Ms. Turk’s apartment with her, but neither of them were present at the crime scene.

Ms. Weaver later confessed to police that she and Machado were involved in the homicide.

A neighbor told police that the couple, Ms. Weaver and Machado, had recently stayed in Apartment 103 and they were seen loading personal property into a maroon or red car around 11:30 p.m. Monday.

Ms. Weaver is known by police to own a maroon or red 1997 Chevrolet Lumina with Ohio registration plates.

When police reviewed the 911 tape, they heard a second female voice saying, “Heather, Heather, did you call the police?” That voice was followed by screaming.

Sgt. Paul Molton of Greenville-West Salem police and state police interviewed Ms. Weaver on Wednesday and she admitted to being at 94 Clinton in the yard by Apartment 103 smoking a cigarette. She said she heard screaming in the home and left.

Machado had told her he wanted to go to that apartment to talk to Ms. Turk about his moving back in there because Ms. Weaver’s mother wouldn’t allow him to stay at her home.

Ms. Weaver saw Ms. Turk on the floor and admitted to making the statement heard on the 911 tape. Machado pushed Ms. Weaver out of the home, saying “Get the hell out of here,” and they left in her car.

Ms. Weaver turned over to police her red sweatshirt, her car and Machado’s shoes, which all had blood on them. She told police Machado used a very large folding knife he always carries.

Molton and state police interviewed Machado on Wednesday at Trumbull County Jail and he said he and Ms. Weaver went to Ms. Turk’s apartment and waited for her to come home.

They called her cell phone from her apartment to ascertain her whereabouts and unscrewed the light bulbs on the first floor to darken the home.

When Lorigan, Ms. Turk and her two children entered the home with milk and other items purchased from Wal-Mart, Machado and Ms. Weaver attacked Lorigan, Machado told police.

Machado and Ms. Weaver both had knives when attacking Lorigan and they also stabbed Ms. Turk. Ms. Weaver stabbed her in the head through the skull and brain, then put her foot on Ms. Turk’s head and pulled the knife out.

She gave the knife to Machado and he stabbed Lorigan in the head. The pair then fled and threw the knives away.

Machado also told police he and Ms. Weaver had discussed over the weekend about killing Ms. Turk and decided to go to her apartment and rob her.

They stole a television and when they left the apartment after the attack, Ms. Weaver also took Ms. Turk’s multi-colored purse, which contained $440 and the children’s identification.

Hardly 48 hours had passed between the crime and charges being filed, which Kochems credited to the hard work of Greenville-West Salem and state police and his office’s detectives, who are still gathering evidence and seeking information from the public.

“It’s not over,” Kochems said of the investigation.

Anyone with information should call Greenville-West Salem police at 724-588-4191.