Family 'Massacred' in Backyard Shooting Near Pittsburgh

A grieving Pennsylvania mother is speaking out about the murders of her three children and two nieces who were killed this week.

"I don't know why they were targeted because they were fun-loving and amongst each other," Jessica Shelton said today of the fatal shooting that happened Wednesday night in the Pittsburgh suburb of Wilkinsburg.

Three of the five victims were Shelton's children: Jerry Shelton, 35, Brittany Powell, 27, and Chanetta Powell, 25. The other two adult victims -- Tina Shelton, 37, and Shada Mahone, 26 -- were their cousins, Allegheny County communications director Amie Downs told ABC News.

The district attorney confirmed that Chanetta Powell was pregnant. Shelton said Chanetta was due in May. The fetus' death was ruled a homicide as well, Downs said.

"I'm just heartbroken. Today, I've got a son who's fighting for his life in critical condition," Shelton said.

All three of Shelton's children were also parents. Jerry Shelton had two children; Brittany just celebrated her daughter's birthday two days ago; and Chanetta had a 6-year-old son and a 8-month-old baby.

Shelton said she was only able to function "because I've got grandkids that I have to be strong for and live for."

Shelton, who attended the cookout but left before the shooting took place, said one of her grandchildren witnessed the tragedy.

"Nana, there was fireworks outside but then I seen Mama and them land on the ground ... [I] didn't want the bad men to see me so I ran upstairs," Shelton recalled.

Police said they believe two men were responsible for the shooting but they have not yet identified any suspects.

Shelton said that in addition to her relatives, there were three men at the cookout that she had not met before.

"My whole family was massacred. Why didn't these three guys get hurt? And they also attended the cookout," Shelton said.

Maurice Trent, pastor of Lighthouse Cathedral in Pittsburgh, spoke at the press conference alongside Shelton, and asked for the public's help in identifying the suspects.

"Somebody knows who did this," Trent said.

"What kind of society are we living in when we can feel good about somebody gunning down women, and a pregnant woman at that," he said.

A $20,000 reward is being offered for any information that will aide investigators in identifying and arresting the individuals involved in the shooting incident, the ATF and Allegheny County Police announced Thursday.