Five people, including three children, were shot to death in a suspected murder-suicide in Emington, Illinois, a farming community 80 miles southwest of Chicago, officials there say.

Police have not yet identified who they believe was the shooter, but a neighbor said today she saw Sara McMeen, 30, shoot her 10-month baby Friday before apparently taking her own life.

Neighbor Annelise Fiedler told The Associated Press that she ran out of her home when she heard gunfire, and saw McMeen hovering over her baby as if she had dropped her. Fiedler asked McMeen if everything was all right.

"She looked at me and said, `No, everything is not all right,"' Fiedler said.

Then McMeen shot the baby, Fiedler told the AP, and Fiedler fled.

Also among the dead are McMeen's other two children, aged 8 and 7, and her live-in boyfriend Daniel Warren, who was 29.

Investigators found three bodies in the backyard, that of McMeen, her young daughter and her baby, and the two other bodies were found nearby.  All had been shot to death, police said.

"At 2:36 today on December 16th, 2011 the Livingston County police dispatch received a call of shots fired in Emington, Ill., which is located in the northeastern portion of Livingston County. Deputies arrived and secured the scene and reported there were five victims," said Martin Meredith, Livingston County Sheriff, according to ABC News affiliate WLS.

Meredith said a semiautomatic pistol was recovered at the scene.

"As your sheriff of Livingston County, I want to make sure everyone understands that you are safe and that the deputies are on the road, and we are looking for no persons of interest at this time," said Meredith today.

Livingston County board member Bob Young said the small farming community is still coming to grips with the horrific deaths.

"Like any small town, nothing like this has ever happened. We're all in a state of shock," Young said.

ABC News Consultant and former FBI agent Brad Garrett said that people reach a breaking point.

"Obviously she reached a breaking point for whatever reason. Was it financial? Were there mental health issues? Was she abused? And she felt like there was no other way out of this and no one would be there to take care of the children and so at this point I'm just going to end it all and kill everybody," he said.

Garrett says the case fits a long established and sad pattern: "Mothers typically kill their spouses and children because they just believe they can't go on any more for financial reasons, for mental health reasons.  Mothers believe that many times that the children are better off if she kills them because their life would just not be worth anything without mom around."

ABC News affiliate WLS contributed to this report.