Police have arrested a 26-year-old homeless man whom acquaintances say may be responsible for several armed robberies on Oahu.

The man was arrested about half an hour after he allegedly robbed Elena’s restaurant at Tropicana Square Saturday in Waipahu.

Honolulu Police Department Maj. Lester Hite said the man entered the restaurant with a T-shirt covering his face about 7:10 a.m., wielding a 12-inch kitchen knife and demanding money.

He left with cash, but witnesses were able to point police in the direction he fled, and officers tracked him down to an apartment complex, Hite said.

The man forced his way into an apartment with two people inside, but officers were able to arrest the man without incident and no one was hurt, he said.

Police arrested the man on suspicion of first-degree robbery and unauthorized entry of a dwelling.

"These crimes, like most crimes, they get solved by community members stepping forward," Hite said. "We’re very fortunate people are willing to step up and guide responding officers or alert officers to the direction of flight."

Hite said police are looking into whether the suspect committed any of the dozens of robberies at businesses over the past few months.

The man whose home the suspect entered asked not to be identified, but said he previously tried to help the suspect, who lives at nearby Waipahu District Park, until the man began stealing from him.

The resident said the suspect entered his apartment sweating and breathing hard Saturday morning and told him he just "did Elena’s."

Mellissa Cedillo, owner of Elena’s, said four employees were inside when the robber walked in. She said the man pulled out a knife, went to the kitchen, and told the women, "Give me your money."

She said the man took less than $100 from the cash register.

"Gunpoint, knife point, whatever it is, it’s scary, super scary," she said. "They come in and holding a knife to my employees, we’re going to fully prosecute."

She said her restaurant is the fifth business to get robbed in Waipahu in just over two weeks.

"Five is enough in Waipahu," she said. "This guy is really bold, whoever he is. We need to catch him."

Residents on Kahuamoku Place, where the suspect was arrested about a block from Elena’s, said the suspect lived with his 18-year-old brother at the park. One woman, who requested anonymity because she is starting a new job, said the younger brother admitted his brother was committing the robberies and said the suspect showed her a rifle that he stored at a neighbor’s home.

She contends the suspect was doing the crimes for drug money.

Another resident, who asked to remain anonymous because of the ongoing police investigation, said the suspect bragged to him about committing at least nine other robberies, including one at Wendy’s restaurant in Mapunapuna on Friday and another at a Wendy’s in Kunia on Wednesday.

The resident said he approached police about the robberies about two weeks ago after the suspect told him he hit a Jack in the Box employee in the head with a rifle during a robbery in Waipahu on July 14.

"When he hit the lady at Jack in the Box, I had enough," the man said. "I tried talking to him. I tried to tell him to get help."

He suspects the man robs for the adrenaline rush.

He said the suspect also showed him a pellet gun that looks like a rifle that he used in some robberies.

"He likes to brag," the man said. "He loves to brag about his money, what he went do. … He bragged to many people about what he did."

He said he notified police when the suspect told him he was going to rob Times Supermarket in Waipahu, which was robbed on Tuesday.

According to the resident, the suspect also admitted robbing two Longs Drugs stores, two 7-Eleven stores, and a bento shop in Waipahu. At least one robbery dates back about eight months.