Naylor Gardens Apartment resident Suzanne Mansfield is seen outside her unit in Southeast Washington on Oct. 16. (Jared Soares/The Washington Post)

The first time the burglars broke into her Naylor Gardens apartment in July, Suzanne Mansfield was in bed and using her iPad. She heard something, then saw a moving shadow.

The registered nurse punched the speed-dial button to ring security, then checked the two other bedrooms of her Southeast Washington home. In her dining room she found the air conditioner on the floor, where it had been pushed from the ground-floor window.

The thieves left her unharmed. But they took two laptops, a solar charging panel and her car keys, which they used immediately to get away in her vehicle. Only two months later, burglars struck again, taking a television, an iPod and an iPad.

“I just felt mad,” said Mansfield, 66, a Naylor Park resident for 20 years. “I just wanted someone to give me a gun. I guess I’m glad they didn’t, because the [thieves] would have stolen it.”

Violent crimes such as homicides have been on the decline in the District and nationwide, but property crimes are a persistent problem. While most thieves are out only for high-dollar items, police are acutely aware that break-ins — such as the two at Mansfield’s apartment — can turn dangerous. They also leave neighborhoods on edge.

At Naylor Gardens, small bands of burglars have struck 18 times across the sprawling, 43-acre complex this year, according to the property’s management office.

The burglars target ground-floor apartments with unlocked windows or air conditioning units. They have even pulled out window frames to slip in and steal computers, televisions and other electronics.

Property manager Alesia Johnson said the burglaries, coupled with a rash of daylight muggings at nearby bus stops last year, led dozens of residents to leave Naylor Gardens.

“We have lost 50 tenants. We normally stay 100 percent occupied,” Johnson said in a recent interview. “It seems a lot of people feel unsafe.”

Rose Zuffi, 56, was one resident who fled. She moved to the neighborhood nearly three years ago after she rode past on a bus and fell in love with the classic brick buildings and well-tended lawns.

But on July 4, thieves raided her home while she attended a picnic in Virginia. She found her apartment in disarray and a 40-inch television and laptop missing. The thieves entered through a bathroom window.

One afternoon about six days later, a D.C. police detective called her to come home. Zuffi thought the police had a lead in her case. Instead, authorities informed her of a second break-in.

“The detective told me to move out, so I moved on campus,” said Zuffi, who is a communications student at Trinity Washington University. “I didn’t sleep there ever again. It’s been a nightmare.”

Sixth Police District Cmdr. Robert Contee said that police officials have increased patrols in recent weeks, and no apartments have been burglarized since September. He said that no police officials would or should recommend that anyone move.

He said the burglary problem expanded beyond one complex to other areas nearby.

“It wasn’t just confined to Naylor Gardens. The common denominator is they were going through first-floor units,” Contee said.

In many cases, as police investigated the break-ins, they found that thieves took advantage of unlocked and open windows, Contee said. Part of the challenge to help eliminate the problem is getting the public to heed warnings about crime.

“Everybody has a part to play in security,” Contee said.

Naylor Gardens spends a half-million dollars annually on private security, Johnson said, and in recent years, the complex has upgraded lighting, installed iron fencing and put security bars on many first-floor windows.

The 24-hour, unarmed security staff and the manager have chased suspected burglars, even following a thief who broke in through a window, stole a bicycle then pedaled away from his pursuers, Johnson said.

One of the property’s strongest selling points contributes to the problem. Its wooded and secluded expanse on the city’s eastern edge offers a serene, almost rural appeal but provides dark places and cover for criminals.

Security officials think teams of three or four culprits work together, sometimes tapping on windows to see whether residents are home, said R.H. Smith, chief of the Colorado Security Agency that patrols there. Guards have interrupted crimes, watching as thieves they chased into the woods dumped laptops and televisions.

But even when security spots burglars or potential burglars, few are arrested because guards either call police before break-ins happen, police arrived too late or police lack evidence.

“The only way you can get them is if you can get them in the act,” Smith said. “The dangerous part is that it’s starting to get dark early, and my guys don’t know what kind of weapons [the criminals] may have.”

Smith said his guards use car and foot patrols, which have had improved success since D.C. police deployed consistent patrols in the past month.

Mansfield and the management office said they are pleased now to see police cars regularly as well as significant attention from 6th District police officials.

And though Mansfield’s car was recovered hours after it was stolen, she fears leaving her home unguarded until the burglars are arrested. She added a home security system and a dog, because, she said, the police response has been “too little, too late.”