A tip helped authorities identify the 47-year-old Pearl City man charged with robbing a 7-Eleven in Kaimuki and suspected of robbing three gas stations during a month-long crime spree.

Joseph Ryan Mookini appeared in U.S. District Court yesterday to answer to one count of obstructing interstate commerce by committing robbery in connection with the robbery of a 7-Eleven at 3105 Waialae Ave.

A conviction under the federal offense could land him in prison for up to 20 years. He was being held at the federal detention center at the airport.

According to an affidavit filed in U.S. District Court, a man wearing a dark colored hat with a shaka sign on the front walked into the Kaimuki 7-Eleven about 3:10 p.m. Nov. 24.

He gave the cashier a plastic bag and said "give me your money" several times.

When the cashier opened the drawer and began to count the money, the robber shouted for the cashier to stop counting the money and reached over to grab the cash.

Another clerk who reached for the robber was punched in the face. When the clerk went around the counter, the robber punched the clerk in the face several more times, causing the clerk to black out and suffer a brain injury, the affidavit says.

Following the altercation, the robber was seen leaving the store in a white van.

After receiving a tip, police arrested Mookini at his home in Pearl City on Tuesday. He was found behind a white van that he drives.

The next day, police searched Mookini’s motorcycle and found inside the saddlebag a plastic replica of a handgun and a dark-colored hat with a shaka sign on the front.

Mookini was charged with affecting interstate commerce because 7-Eleven does business across state lines.

Police said Mookini’s crime spree began Nov. 7 when he robbed a 76 Station in Pearl City, then the Tesoro on Dillingham, the 7-Eleven in Kaimuki, and the Island Mini Mart on Kapahulu on Dec. 3. 

In each robbery, the robber brandished what appeared to be a hand gun.

The case was investigated by the Honolulu Violent Incident Task Force, comprised of the Honolulu Police Department, FBI, and the Bureau of Alcohol, Tobacco, Firearms and Explosives.

ATF Resident Agent-in-Charge Jordan Lowe said the other three robberies are being investigated, and Mookini will probably face charges for those robberies in the future.