EL CAJON, Calif. — A San Diego County judge has ruled that a man must face trial for the murder of his girlfriend with a cannon-like device.

U-T San Diego reports (http://bit.ly/12ESXvw ) Judge Evan Kirvin said Wednesday the prosecution had presented enough evidence for Richard Dale Fox to stand trial on charges of murder, exploding a destructive device causing death and child endangerment.

The 40-year-old faces life in prison if convicted.

Prosecutors say Fox was drinking with friends in the San Diego County town of Potrero when he set off the device, sending shrapnel into his trailer that killed 38-Jeanette Ogara. They say Ogara was Fox's girlfriend and the mother of his 4-year-old daughter.

Defense attorney Thomas Slattery called the death a freak accident.

Fox has pleaded not guilty to all three charges.