Los Angeles (CNN) At least four people were shot dead and two others were wounded Thursday in Los Angeles before the gunman was captured, authorities said.

Gerry Dean Zaragoza, 26, killed his father and brother at their home, fatally wounded a woman he knew at a gas station and shot a man on a bus who died, police said.

There is no obvious motive for any of the killings, said Capt. William Hayes of the Robbery-Homicide Division of the Los Angeles Police Department.

"We're evaluating it, we're interviewing witnesses but we can't come up with a specific answer," he told reporters.

Hayes said the shootings began at about 1:20 a.m. in Canoga Park when Zaragoza shot his parents and brother. Zaragoza's father and brother were killed and his mother injured, Officer Greg Kraft said.

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