A mother of four was found brutally beaten to death in the back yard of her Lancaster County home. A murder investigation is now underway.

There are many more questions than answers - who did it and why? Jan Roseboro, by all accounts, was a pillar of the Reinholds community. She helped out with the local swim team and volunteered with an environmental group.

People who knew the 45-year-old woman say she was very active in community. Roseboro volunteered with the East Cocalico Swim Team alongside of Joe Maurizi. He couldn't believe she was gone.

"Jan was very ... always had a smile on," he said. "Never had a bad thing to say about anybody. Was always willing to go an extra mile for the kids and for the team."

Police say Tuesday night, Roseboro's husband Michael called 911 and reported he found Jan unconscious in the family swimming pool. Officers arrived at the house on West Main Street to find Michael performing CPR on his wife. After an autopsy, investigators determined her death was no accident. She was murdered.

"She had extensive injuries to many different parts of her body that are consistent with multiple blunt force trauma," said Lancaster County District Attorney Craig Stedman. "A beating. In addition to that, the other cause of death was drowning. Somebody brutally assaulted her and drowned her."

The family's yard is enclosed by a metal fence. Investigators say there were no signs of forced entry and no signs of a struggle. At this point, police are not naming any suspects.

"We ask for cooperation from the community, from friends of hers, from people that knew the family to come forward an cooperate with us. Obviously, we've got a murderer out there. We've got a crime to solve - a tremendously serious crime," said Stedman.

Meanwhile, police continue to interview neighbors and family members. We're told the Roseboros had a get-together at their home earlier that evening.

Investigators say no adults other than Jan's husband were around at the time. As for the Roseboro's four kids, there's no word if they were home. We asked if detectives found any weapons at the scene, but the district attorney couldn't comment.