OKLAHOMA CITY - A quadruple murder has left a community in shock.

The man police say is behind the murders is in custody. But now investigators, family and neighbors are all trying to figure out why this happened.

Daniel Green, 40, sits in jail for the murders of four family members. Police were called just before 11 p.m. Thursday to a house in the 4600 block of S.E. 79th Street, which is near Interstate 240 and Sooner Road.

Inside the home, officers found the bodies of Green's mother Sallie Green, 57; his niece Katherine Cizek, 16; sister Rebecca Cizek, 34; and nephew Amario Dominguez, 7 months.

Neighbor Rhiannon Baker couldn't believe it happened right across the street.

"I lost it," Baker said. "That was the first thing I asked the cop, was there a baby in there, is the baby okay? And he just kind of shook his head and I just lost it."

Katherine Cizek was just about to begin her sophomore year at Del City High School. The school board released the following statement Thursday afternoon:

"The faculty and staff of Mid-Del Schools is mourning the loss of one its students today, Katherine Cizek, Del City High School sophomore. We extend our heartfelt sympathy to the family during this time of tragic loss. Thank you for your concern at this difficult time."

While neighbors were shocked about the murders, they weren't as surprised Daniel Green was a suspect.

"He's kind of weird," said Diana Brewer, another neighbor. "Walks up and down the street. He was always out front. I don't want to be rude or disrespectful, he was just kind of weird, but I mean I would never think that he was capable of anything like that."

Detectives mounted a quick effort to identify and find Green. They caught up with him near a convenience store after a clerk tipped them off.

Police still have not confirmed how the victims were killed, but neighbors said police asked them if they had heard gunfire, leading many in the neighborhood to believe the victims were shot.

According to court records, Daniel Green has prior convictions on weapons and drug charges.