By SUMMER BALLENTINE, Associated Press

JEFFERSON CITY, Mo. (AP) — Republican Missouri Gov. Eric Greitens on Tuesday signed legislation to change the standard for vetting expert witnesses in jury trials, a move he touted as a way to boost the economy by improving the legal climate for businesses in the state.

The legislation will require judges gauge the quality of expert witnesses, requiring their testimony to be based on "sufficient facts" and "reliable principles" that are appropriately applied to cases.

Greitens said the goal is to ensure experts "are actually experts" and calm fears of lawsuits toppling businesses.

"When crooked trial lawyers bring in shady witnesses that act as experts while peddling junk science, it makes it harder for justice to be done," Greitens told reporters during a visit to a Jefferson City trucking company, where he signed the bill. "That scares away businesses and means fewer jobs and smaller paychecks."

The law takes effect Aug. 28.

A similar bill passed the Republican-led Legislature last year but was vetoed by former Democratic Gov. Jay Nixon, who generally opposed GOP efforts to put restrictions on lawsuits.

Critics of changing expert witness policies say doing so can ramp up costs and make seeking justice more difficult for plaintiffs. Kansas City attorney Ken Barnes said that's because challenging witnesses' expertise likely will require hearings, which can mean paying experts for time spent explaining themselves to judges and more attorney fees.

"I do not believe this is in any way is going to benefit the citizens of Missouri," said Barnes, a leader of the Missouri Association of Trial Attorneys. "I don't think it adds any justice. I don't think it will improve the quality of experts."

He also said the new standard will require judges to decide whether experts are reaching the right conclusion based on evidence. He said that can be challenging on issues on which experts disagree.

Greitens' action brought praise from groups including the Missouri Chamber of Commerce and Industry, Washington, D.C.-based American Tort Reform Association and U.S. Chamber of Commerce. Lisa A. Rickard, president of the U.S. Chamber's Institute for Legal Reform, said in a statement that Missouri is "turning the corner on legal reform."

The measure is part of a broader push from Greitens and Republican legislative leaders to overhaul state law dealing with torts, which are wrongdoings. Tort cases range from medical malpractice to consumer fraud such as sales of lemon cars.

Greitens said his next hope is that lawmakers change state policies that determine where lawsuits can be filed and the ability of plaintiffs to join together in lawsuits. Bills to do so are pending in both the House and Senate.