California led the nation in drive-by shootings during a six-month period in 2008 with 148 reported shootings that killed 40 and injured 129, according to a study released yesterday by a national nonprofit educational organization.

The Violence Policy Center used Google News to collect articles with the words "drive by" in them from July 1, 2008 to December 31, 2008, and then filtered the results for its Drive-By America study.

The study found a total of 733 drive-by shooting incidents in the U.S. that killed 154 people and injured 631.

When it comes to California, 39 percent of the shootings happened at a residence (although a location could not be verified in six of the 148 shootings). Forty-two percent of them occurred between 7 p.m. and midnight (although 13 of the 148 shootings did not include a time).

Seventeen percent of those dead or injured in California were said to be under the age of 18, and 32 percent of the news reports noted "potential gang involvement."

The study's authors concluded that more research is needed nationally if "effective prevention strategies" are to be pointed out.

The study recommends looking into whether a drive-by-shooting category could be added to uniform crime reports; having communities with higher instances of drive-by shootings collect their own information on them; and having state and federal policies "focus on limiting the caliber and capacity of firearms marketed to the general public."

But the Violence Policy Center wrote in its report that the results may not be as high as they should be:

"Recognizing the limitations of the survey tools used, and taking into account prior studies looking at the number of drive-by shootings in specific jurisdictions, it is likely that the number of shootings is dramatically underreported.The number of reported instances may also be influenced by local media focus."