Updated

Los Angeles police on Thursday detained a 15-year-old Phoenix boy in connection with a shooting in a smoke shop in Peoria, Ariz., which left two people dead and a third injured.

Police said the shooting occurred inside The Euphorium Emporium near Lake Pleasant Parkway about 1:30pm local time Tuesday, when a gunman entered the store and fired off several shots, hitting three of the four people inside, 3TV News reported.

When a SWAT team arrived at the scene, they found Kenneth Matlock, 60, and Melinda Bowen, 38, dead in the store.

Another customer, Robert Troutman, 51, ran out of the store after being shot and was later airlifted to a local hospital for treatment of a non-fatal gunshot wound to the hip.

The suspected gunman, Tyson Drew Langley, was arrested Thursday near a Greyhound bus station in Los Angeles after beat officers were issued with a "be on the lookout alert" at the morning briefing, police spokesman Lt. Paul Vernon said.

Police found a semi-automatic handgun inside a bag next to the teen and police have detained him on a weapons charge, the Arizona Republic reported.

Court documents cited by KPHO-TV revealed the incident began as a robbery, with the gunman holding up the store owner -- who fled -- then opening fire after Bowen entered the shop, followed by the other customers.

During the robbery, Langley took about $300 from the register, the documents stated.

Police from Peoria were traveling to Los Angeles and Langley was likely to be extradited to face murder charges.