Local law enforcement can decide if they want to hold illegal immigrants on behalf of the federal government, California Attorney General Kamala Harris said Tuesday.

At question is Secure Communities, an Immigration Customs and Enforcement, or ICE, program launched more than two years ago in the Sonoma County Jail and as far back as 2008 elsewhere.

The program uploads fingerprints and other biometric data taken when people are booked into local jails and checks them against vast criminal and immigration databases.

ICE agents may then ask jails to hold a person for 48 hours beyond the time they are supposed to be released, and federal authorities have insisted jails must honor their requests.

But Harris said Tuesday that the system is flawed and puts undue strain on local agencies already strapped for funds, staff and space.

Sonoma County Sheriff Steve Freitas said it's too soon to decide whether he will make any changes to how they handle federal requests for what's commonly called an "immigration hold."

"The federal government has said consistently that it is mandatory," Freitas said. "Some of the other language says differently. It's a very confusing issue."

When the program launched locally in March 2010, then-Sheriff Bill Cogbill said he had no choice but to participate in the program.

Harris outlined her analysis in a bulletin sent Tuesday to agencies across the state. Freitas said he asked county counsel to review the memo and take another look at federal instructions.

"They're going to need to do a legal analysis because the federal government doesn't agree with her," Freitas said of the attorney general's analysis.

When ICE began rolling out Secure Communities in local jails in 2008, critics said local agencies shouldn't be required to enforce federal immigration laws.

Immigrant advocates and some in law enforcement blasted the program out of concern it would prevent immigrants, fearing deportation, from reporting crimes.

Federal officials claimed the program helps identify violent and repeat criminals who are illegally in the country.

In its first year, 47 percent of immigrants Sonoma County turned over to immigration agents under Secure Communities were not convicted of the crimes that landed them in jail, according to data provided by ICE.

Harris said her office has received dozens of inquiries from sheriffs and police chiefs confused about whether they must comply and hold detainees.

<NO1>Los Angeles Police Chief Charlie Beck and others have said they want to stop honoring the immigration detention requests in cases involving low-level crimes.

Santa Clara County and Cook County, Ill., previously stopped holding inmates on behalf of the federal government flagged by Secure Communities.

Last fall, Gov. Jerry Brown vetoed a bill to limit law enforcement involvement with Secure Communities.

Harris' bulletin asserts that the federal government can't "require state officials to carry out federal programs at their own expense."

<NO><NO1>"In the interest of public safety, it is our recommendation that those chiefs and sheriffs make a decision about whether or not they will detain an illegal immigrant based on their priorities," Harris said.

<NO>The Sonoma County Jail forwarded data from 20,783 inmates to ICE in the 11-month period ending Aug. 31, 2012, the most recent figures available.

Sonoma County inmates were handed over to ICE custody at a rate of 44 people per month during that time period, according to a Press Democrat analysis.

In Sonoma County, the jail can handle people on federal immigration detainers, but there isn't necessarily enough staff to manage them, Freitas said.

"We have bed space in the jails, so it's not necessarily a space issue," Freitas said. "It could be, to some extent, a financial issue."

You can reach Staff Writer Julie Johnson at 521-5220, julie.johnson@pressdemo crat.com or on Twitter @jjpressdem.