The Los Angeles County Board of Supervisors voted Tuesday to pursue a potential ballot measure that would tax top-income earners to combat rising homelessness. Supervisors also agreed to conduct an internal audit of how the county spends money on homelessness.

In a 3-2 vote, the board directed its top executive and the county’s legislative advocates in Sacramento to pursue a change in state law to grant counties the authority to seek a ballot measure for a tax on personal income above $1 million a year, which would generate about $243 million a year.

In addition to the tax, other options to raise money for homeless programs include a marijuana tax, a parcel tax and redirection of Measure B trauma tax funds.

“It is a crisis — no one can deny that,” Supervisor Mark Ridley-Thomas, who introduced the motion with Supervisor Sheila Kuehl, said before the vote. “It is the most compelling issue confronting us at this time.”

The county has “a moral obligation” to fight the increase in homelessness and ensure those suffering from a range of maladies are “restored to health, dignity and purpose” while becoming contributing members of their communities, Ridley-Thomas said.

Supervisors Michael D. Antonovich and Don Knabe voted against seeking the authority from the state Legislature and Gov. Jerry Brown to pursue the personal income tax measure on wealthy income earners.

Antonovich said many of those who are homeless are mentally ill and need to have mandated mental health therapy or rehabilitation programs for addiction. State laws also need to be changed so the mentally ill receive more than 72-hours of mandatory care, he said.

“Just having another revenue source to build a house is not addressing the root cause for those people who are mentally or physically ill,” Antonovich said. “They need medical treatment.”

More than 100 people spoke Tuesday in favor of seeking the potential ballot measure to tax wealthy income earners. Among them was Ed Bernard, who is currently homeless and is the beneficiary of nonprofits such as Sanctuary of Hope in South L.A.

“I just want to continue to get that support for homeless youth and also the homeless around L.A. County,” he told the board.

A change in state law would require a simple majority vote in the state Legislature. If ultimately placed on the November ballot, the measure would need two-thirds voter approval to pass.

To provide more data and analysis, the board also unanimously directed staff to work with public health officials, the sheriff and the interim chief probation officer to examine how county funds for homeless services are spent each year. The audit would especially focus on the resources allotted to 5 percent of homeless single adults who utilize 40 percent of this funding.

The county spent $965 million on single homeless adults in fiscal year 2014-15, Supervisor Hilda Solis said.

“This tells me that we need to step back and take a hard look at the way we’re currently addressing the problem,” she said.

The county now has an estimated 46,874 homeless people on any given night, up 5.7 percent from last year, the Los Angeles Homeless Services Authority announced this month. The agency found a 20 percent increase in the “most visible form of homelessness” — people living in tents, vehicles and encampments over 2015 numbers.

Polling results released in April found that about 76 percent of likely voters in the county would strongly support a November ballot initiative to impose a one-half percent tax on income above $1 million.

David Kline of the California Taxpayers Association argued that the state already has the highest personal income tax rate in the nation.

“The best way to fight poverty in California is to foster an environment that welcomes and promotes good-paying jobs, not to impose additional taxes that make it harder to keep a business open,” Kline said in an email.