The late night break-ins have taken place in Stevinson, Hilmar, and just outside of Atwater. Deputies say the elderly are often targeted because they're seen as easy victims.
Now the sheriff's department is encouraging all seniors to take a few simple steps that can help keep them safe.
The most recent and most violent attack against an elderly woman in Merced county happened on a rural road near Atwater.
Sheriff's deputies say a man broke into the woman's home through a patio window, knocked her to the ground, and tried to rape her. But the 70 year old fought back, and the man eventually ran from her home.
Other seniors in the area heard about the attack and say now they're taking extra safety precautions.
Viola Hines, Atwater resident, says "I was in the habit of leaving my doors open in the front and the back, but this like I said is a wake-up call, I will not do that anymore."
This latest break-in follows two other recent incidents in which elderly women woke up to find strangers in their homes. And authorities are still investigating the rape of an 80 year old woman who was seen on a gas station surveillance video with her attacker in November.
Deputy Tom Mackenzie, Merced County Sheriff's Department, says "We're not suggesting there's a pattern or any relationship, we just want people to be aware that this is going on."
Deputy Mackenzie says the department also wants seniors to know there are ways to protect themselves...like installing alarms and forming neighborhood watches or other support networks.
"Get in touch with your neighbors, make sure your relatives and family and friends check on you," says Dep. Mackenzie.
Viola Hines says even with her dog at her side, she's not taking any chances. "I'm going to leave those patio lights on now. And I think that's what a lot of us should do, you know?"
Sheriff's deputies say sometimes seniors are hesitant to report crimes because they're afraid of losing their independence if relatives worry about their safety. But authorities say they need the elderly to come forward in order to better protect the community.