St. Mary's County authorities arrested employees or former employees of four businesses over the past five weeks, charging them in connection with robberies and thefts that targeted their employers.

In the most recent arrest, detectives allege that Javarus Swales, 20, used a pencil to prop open a side door at the Checkers hamburger restaurant in California. That allowed two gunmen -- one of whom was a former Checkers employee -- to enter the restaurant after closing time. The gunmen forced the employees (including Swales, the alleged pencil propper) to lie on the floor in office area.

The next day, according to allegations contained in court records, Swales was offered a cut of the approximately $3,000 taken in the robbery.

Authorities allege other inside jobs have occurred at a McDonald's in Charlotte Hall and outside a Papa John's and outside the Mattress Corner store, both in Lexington Park.

At the mattress store, a former employee is accused of holding up a 78-year-old salesman, who was walking out of the store after closing. The suspect allegedly had an accomplice who was an employee of Papa John's. On a different night, the two of them robbed two Papa John's employees of restaurant money in the parking lot of the pizza place, according to court records.

And in a fifth case, a cashier at the Food Lion in California was charged in December with dipping into the cash register as many as four times a day -- removing as little as $1 and as much as $41.23 at a time -- actions captured on surveillance equipment.

Authorities say they don't know whether such incidents are increasing, because they don't keep statistics specific to employee-against-employer crimes. But they called employee-related thefts a chronic problem and suggested that business owners install digital monitoring technology in place of older videotape systems that are more susceptible to tampering.

The Checkers case was solved with the help of modern monitoring equipment. Investigators studying images captured by cameras inside the Checkers concluded that Swales was "acting nervously" as he worked near the drive-through window, according to charging documents in the case. The monitoring equipment also indicated that he was the only employee in the area of the door that had been propped open, according to charging documents.

During employee interviews, authorities said, it became clear that someone inside the business had assisted the robbers. Swales eventually "acknowledged placing the pencil in the door" to prop it open, detectives alleged in charging documents.

A manager at Checkers on Tuesday declined to comment on the incident. She said the owners did not want to discuss the case.

St. Mary's County has an unemployment rate of less than 4 percent. Employers in the county say it is hard to find workers.

"It's not very easy these days to find good people," said the owner of Centre Liquors in Leonardtown, who goes by Kumar. He said his two employees are good.

A tour through Centre Liquors indicates the growing affluence of St. Mary's. Kumar said in the seven years he has owned it, he has expanded wine offerings. Bottles on the shelves cost as much as $70.

A St. Mary's restaurant operator, who asked not to be named, blamed the growing affluence for making it harder to fill the lower-wage jobs at fast-food restaurants and small retail businesses.

Whatever the factors, said Lt. Daniel Alioto, commander of the St. Mary's Sheriff's Office patrol division, "you hear from all employers that it's harder to get help, period."

He said employers can run a criminal background check. They can access the Maryland judicial case records online at http://casesearch.courts.state.md.us/inquiry/inquiry-index.jsphttp://or conduct a simple Internet search.

"People are Googling each other before they're going on dates now," he said, adding that employers can do the same before hiring.

Others charged in connection with the recent incidents are:

· Former McDonald's employee Charles R. Reid IV, 19, of Hollywood, who was charged with theft and reporting a false crime in connection with what authorities allege was a staged robbery.

· Demetrick N. Maddox, 19, of Great Mills, who authorities said was one of the Checkers gunmen.

· Steven K. Scott, 18, who has worked at Papa John's; and Martese D. Thomas, 30, a onetime employee of Mattress Corner.