Police try to find motive for San Bernardino shooting rampage

Couple were armed with 1,600 bullets; left behind 3 pipe bombs

The two attackers who killed 14 people in a gun rampage in California fired up to 75 rifle rounds, left behind three pipe bombs and had over 1,600 more bullets with them when they were gunned down.

At their home, they had 12 pipe bombs, tools for making more explosives, and more than 3,000 rounds of ammunition, Police Chief Jarrod Burguan said.