OAKLAND, Calif. -- Facing pressure to crack down on crime amid a record budget deficit, Oakland is joining other U.S. cities that are turning over more law-enforcement duties to private armed guards.

The City Council recently voted to hire International Services Inc., a private security agency, to patrol crime-plagued districts. While a few Oakland retail districts previously have pooled cash to pay for unarmed security services, using public funds to pay for private armed guards would mark a first for the city.

Hiring...