GLENDALE, ARIZ. ? Two Wal-Mart employees were shot to death Tuesday as they gathered shopping carts in the parking lot of one of the retail stores in suburban Phoenix, and police later arrested the suspected gunman.

The shootings occurred in the middle of the parking lot, about 75 yards from the store entrance. At one point, a body could be seen in one of the corrals used for collecting shopping carts.

Hours later, police spokesman Mike Pena said a suspect had been arrested without incident in a retirement community in nearby Peoria.

The suspect, described as being in his 50s or 60s, still needed to put through a lineup and questioned by detectives. His name was not released.

There was no immediate word on what might have motivated the attacks.

Delia Garcia, a Wal-Mart spokeswoman on the scene, said the two victims were collecting shopping carts when the gunfire broke out. She said the store would be closed at least until this morning.

Authorities initially kept customers inside the store, but they were later allowed to leave.