A motive has not yet been established
Ayman bin Mohammed abu Zinad, 30, was named by the Saudi Interior Ministry as the perpetrator behind the blast on 6 October in the eastern town of al-Khobar, but a motive has not yet been established.
The blast - which took place outside an electronics shop - injured a further four people: another American, a British citizen and two Filipinos.
But it is yet unclear if the mission was intended as a suicide attack, or whether the bomb went off accidentally.
Blast theories
Abu Zinad worked as a dentist in the Saudi capital Riyadh, but his family lived near al-Khobar in the city of Damman, where he usually spent the Muslim weekend.
Investigators found bomb devices at his family home as well as identification papers, including two Indian passports.
There was much speculation last month that the attack was linked to the US military build-up in the region ahead of its campaign against Afghanistan.
Al-Khobar is near the former military base at Dhahran, where American troops were stationed until 1996 when a bomb blast - blamed on Islamic extremists - killed 19 US servicemen.
That attack drove the American forces to relocate to the desert.
It was also suggested that the blast was one of a series of attacks against foreigners in Saudi Arabia, which police have linked to illegal alcohol trafficking.
Drink links
At the end of last year and the beginning of this year, Saudi Arabia was rocked by a series of bomb blasts.
Diplomats in Riyadh and Saudi newspapers said at the time that the attacks were linked to alcohol trafficking - selling and drinking alcohol is strictly forbidden in Saudi Arabia.
Three British men were arrested in Saudi Arabia in connection with some of the bombings and were shown confessing on state-run TV.