Mum, daughter charged with killing five relatives due in court

Shana Decree, left, and her daughter Dominique Decree who are charged in the killing of their relatives. Photo / AP

A mother and her adult daughter charged with killing five of their close relatives, including three children, at an apartment outside Philadelphia in the US have appeared together in court.

Shana Decree, 46, and her daughter Dominique Decree, 20, each pleaded not guilty to five counts of homicide and one of conspiracy at the Common Pleas Court in Doylestown on Tuesday, local time.

The pair barely spoke, except to respond to the judge's questions about the charges and their pleas. At one point, sounds of crying emanated from the defendants' table, and Dominique wiped her eyes. Shana closed hers briefly as the judge read the names of the victims.

Police say they found Shana and Dominique Decree "disoriented" inside the apartment. Photo / AP

The family members' bodies were found in their trashed apartment in Morrisville a year ago, according to authorities.

The victims were Shana's children, Naa'Irah Smith, 25, and Damon Decree Jr, 13, both of Morrisville; Shana Decree's sister Jamilla Campbell, 42, of Trenton, New Jersey; and Ms Campbell's nine-year-old twin daughters, Imani and Erika Allen. Ms Smith, Damon Decree Jr and the twins had been suffocated, the Bucks County coroner's office said in March. Ms Campbell had been strangled, according to the coroner.

Authorities made the gruesome discovery after a child welfare officer arrived on an unannounced visit and was let into the building by someone who worked there, according to court papers.

Nine year-old twins, Imani Allen (Left) and Erika Allen (Right) were the youngest victims. Photo / news.com.au

Police say they found Shana and Dominique Decree "disoriented" inside the apartment, where furniture had been turned over, drywall was cracked and glass lay around.

Police initially said they found four bodies, but they discovered a fifth underneath another that was next to a bed.

The apartment is in a three-storey, red brick complex in Morrisville, which sits on the Delaware River northeast of Philadelphia and across from Trenton.

Prosecutors confirmed on Tuesday that they filed first-degree murder and conspiracy charges against the pair and have until March 20 to decide on seeking the death penalty. A trial is set for June 8.

Naa'Irah Smith was one of the five family members murdered, Shana Decree daughter. Photo / via Facebook

Deputy District Attorney Christopher Rees said after Tuesday's hearing that a possible motive could become clearer during the proceedings.

"I feel like the questions are: Why did this happen? Why did this happen? Why did this happen? It's the same question I have because it does seem so hard to understand," he said. "It's such an unimaginable crime."