(Associated Press) Former Arizona Sheriff Joe Arpaio was unable to cite any evidence on the witness stand Wednesday to back up his now-dismissed animal cruelty case against one of U.S. Sen. Jeff Flake’s sons in the 2014 deaths of 21 dogs.

The former six-term sheriff of metro Phoenix told jurors he felt his detectives had gathered the proper evidence to recommend charges after the dogs died of heat exhaustion. He repeatedly declined to explain his confidence in the investigation into Austin Flake and his then-wife Logan Brown, who were caring for the animals at a kennel operated by Brown’s parents.

“Once again, I don’t have the nuts and bolts,” Arpaio said. “The detectives handled it.”

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