LOS ANGELES, Calif.—An independent police department watchdog has concluded in a report about to be presented to the Los Angeles Police Commission that there was no link between the dramatic rise in officer-involved shootings last year and assaults on officers, as police Chief Charlie Beck contends, it was reported today.

Alex Bustamante, the inspector general for the Los Angeles Police Commission, which oversees the LAPD, scrutinized the 2011 assault and shooting figures for a report he will present to the commission Tuesday. In it, he challenged the way the LAPD tallies assaults on officers, suggesting it is misleading, the Los Angeles Times reported.

LAPD officers fired their weapons in 63 incidents last year, a roughly 50 percent increase over the shootings in any of the previous four years, according to the report.

Beck has explained the increase by pointing to what the LAPD said was a 22 percent increase in assaults on officers from 2010 to 2011. Police officials counted 193 such incidents in 2011, recording them as assaults with a deadly weapon or attempted murders, according to the report.

"Officer-involved shootings are also up—largely in response to these kind of attacks," Beck told the Police Commission in November, according to The Times.

But the inspector general found several reasons why he said this cause-and-effect relationship wasn't accurate, The Times reported. For one, from 2007 to last year, the number of assaults on officers fluctuated dramatically from one year to the next. The number of officer-involved shootings, however, remained relatively flat until last year, when they jumped.

If there had been a connection between the two, the year-to-year totals should have climbed and dropped in sync, according to the report quoted by The Times.