"I let my dogs out and yelled at them to get out of my yard," Rooker said.

The young men retreated but not without a exchange of words. "He asked me, 'What are you going to do about it?' " Rooker said. "My dogs were in attack mode and he said, 'These dogs can't get me,' before disappearing."

Rooker believes the young men climbed onto a garbage dumpster to reach the concrete wall that divides Summercrest Villas--an affordable seniors-only apartment community in Willow Glen--from the residents on Guadalupe Avenue. Then the men jumped over her fence.

There is a thin gap between the residents' fences and the wall.

The concrete wall, about 6 feet tall, runs parallel to the backyard fences of homeowners living along Guadalupe Avenue.

"The trees block the view from the apartments, making it easy for the men to climb over without being seen," Rooker said.

She called the police immediately but the men had already disappeared.

No one was hurt, but the incident is causing jitters among residents living next to the apartments, and similar stories of intrusion have surfaced since Rooker contacted the police.

Last year, William Kiley, a 35-year resident, found some tools stolen from his garage. He says he believes that one or more intruders got into his backyard by climbing over a wall on the senior housing property.

The senior housing development has an open driveway that allows easy access into the complex, Kiley said.

Rooker's neighbor, Armida Campa, suspects that somebody tried to break into her house in January while her husband was on a business trip.

She noticed a bathroom window out of place one morning but didn't find anything missing. The window looked as if it had been removed and then reinstalled incorrectly.

"I felt scared. I couldn't sleep," Campa said. "I don't feel safe anymore."

Her husband recently bought a pit bull terrier to safeguard their property.

Clifford Scott, who owns a kitchen remodeling and cabinetry business next to the senior housing development, has also experienced problems. His business shares a concrete wall with Summercrest Villa.

"Six months after the senior housing development came up, we started noticing things being stolen here and there," Scott said.

He has had copper tubing worth about $100 stolen. Three months ago, he realized his boat had been broken into. A GPS system, a two-way marine radio and a lifejacket were missing from the boat parked at his workplace. Scott installed security cameras at his shop to prevent further thefts.

Residents believe the increase in crime activity is a result of the easily scaled low walls surrounding the senior housing development.

"People are going through the development and getting access into our backyards," Riley said.

Before the senior housing development was constructed in 2003, a tractor-rental company occupied the lot, which was secured by cyclone fencing with barbed wire all around. Kiley also remembers a security guard regularly patrolling the property.

After the incident at Rooker's home, she contacted Summercrest Villa property management to see if the residents and the managers could work out a solution.

The management put a chain and lock at the side gate along Willow Glen Way to discourage people from cutting through the property as a short cut to the grocery store on that street.

Since they have locked up that gate, Tom Knight, regional manager for the complex, added that his staff has noticed some young people attempting to jump over the wall to get to the stores and have strongly discouraged them.

"We are going to place a 'No Trespassing' sign at the entrance of our property and work with local law enforcement agencies to stop this traffic," Knight said.

Residents are glad that steps are being taken to improve security, but hope more can be done, such as putting wired fencing atop the wall, hiring security, installing security cameras or raising the height of the walls.

Knight said that these are possibilities the management and residents along Guadalupe Avenue can explore together. "We are going to try to make every effort to make the neighborhood safe," he added.

Rooker now keeps a backlight on and has one of her dogs sleep in the kitchen, facing the backyard. Kiley has installed cameras on his property and is thinking about getting a dog.

"We've had our fair share of parties that were too loud or families fighting each other in the neighborhood, but we never had so much activity before," Rooker said. "It used to be a nice, quiet neighborhood and we want that to return."