SOUTH PASADENA — Two South Pasadena men are behind bars on suspicion of robbing a man in Temple City who was trying to buy an iPhone through Craigslist.com earlier this month, authorities said Sunday.

Daniel So, 19, and Garret Helstrom, 20, were booked on suspicion of armed robbery Friday after being arrested near So’s home, Los Angeles County sheriff’s officials said in a written statement.

The robbery was reported about 3 p.m. on Feb. 19 in a parking lot behind a fast-food restaurant in the 9400 block of Las Tunas Drive in Temple City, sheriff’s Sgt. Jeff Walker said.

The man had arranged to meet someone via the website Craigslist.com to buy an iPhone for $500 and met So in the parking lot to do the transaction, Walker said.

Instead of an iPhone, the So pulled a gun and demanded the man’s money, officials said. The man fled after turning over his cash and was unhurt.

Sheriff’s investigators identified So as a suspect in the robbery, went to his South Pasadena home Friday and watched as So got into a car with another man, later identified as Helstrom.

Deputies pulled over the car and arrested So, according to the sheriff’s statement.

When deputies found a handgun replica and what appeared to be stolen property in the car, officials said, Helstrom was also arrested for assisting in the robbery.

According to sheriff’s booking records, So and Helstrom were being held in lieu of $100,000 bail each at the sheriff’s Temple Station.

Detectives are looking into the possibility the men may be responsible for other similar crimes, and anyone who’s been a victim of a similar robbery is asked to call their local police or sheriff’s station.