U.S. Sen. Patty Murray wants the FBI to increase its number of agents in Washington state, telling FBI Director Robert Mueller in a letter on Monday that comparatively low FBI staffing increases the state's vulnerability to terrorism and affects the agency's crime-fighting ability.

But Murray, D-Wash., does not want Mueller to reassign agents from other states, said her spokesman, Matt McAlvanah. Instead, Murray wants Congress to give the FBI more money in the future.

This year, Congress provided $5.9 billion and later added $258 million in a supplemental appropriation.

Murray has not specified the amount of the desired spending increase for coming years, McAlvanah said.

In her letter, Murray cited recent articles in the Seattle Post-Intelligencer that determined the national FBI average — excluding the large FBI presence in the District of Columbia, Virginia and New York — is about three agents per 100,000 people.

Washington state, Murray wrote, has only slightly more than two agents per 100,000 people and is 35th among the states in FBI agents per capita.

With a population of about 6 million, Washington has 133 agents, 53 fewer than the 186 agents needed to bring it up to the national average, Murray wrote.

Murray also noted the state has several international seaports, military installations and an international border with Canada. "Given the number and importance of potential targets, I am concerned that the small number of FBI agents in Washington state may have an adverse effect on the safety and security of our citizens," she wrote.

Alex Fryer: 206-464-8124 or afryer@seattletimes.com