CHESTER — State law enforcement officials Friday tried to charge Chester County Sheriff Robby Benson with domestic violence, but the local magistrate refused to sign the warrant.

Chief Magistrate Dianne Moore, who has worked with the sheriff for a decade, said there wasn’t enough evidence that Benson had injured his wife, Marcy, during a March dispute.

“We were ready to prosecute a man for criminal domestic violence and the judge ended this matter today,” Mark Plowden, spokesman for the state attorney general, said.

“In the state of South Carolina, a judge has the power to sign or not to sign an arrest warrant, and that’s the way the laws are set up ... we can’t re-write the rule book.”

The sheriff’s lawyer called the magistrate “neutral and detached” and said the criminal justice system had worked.

Neither the sheriff nor his wife would comment Friday.

Benson, 45, and his wife, Marcy, 34, have not been living together since January, according to court documents.

In March, three days before the sheriff filed for legal separation, the couple argued behind a Wendy’s in Chester where Marcy Benson was employed, according to public documents.

They met to talk about “their marriage problems,” a sheriff’s report said.

Marcy Benson told a deputy who responded to the scene that she had attempted to block her husband from getting into his vehicle when he wanted to leave, according to the incident report.

Robby Benson then “grabbed the victim and threw her out of the way,” causing her to fall on the pavement, the report stated.

While considering whether to sign an arrest warrant Friday morning, Moore said she saw the pictures but did not think there was enough information that Benson “did it.” She also said the evidence presented by State Law Enforcement Division officials did not “rise to the level necessary to issue a warrant.”

The attorney general’s office said it was convinced its evidence, which included pictures of injuries to Marcy Benson’s left hand and right knee, would ensure an arrest warrant and came prepared for a bond hearing.

Moore was the only Chester County official who remained involved in the case. To avoid a conflict of interest, the county solicitor passed the case on to the attorney general’s office. SLED investigated.

The attorney general’s office said it asked Moore if she needed to recuse herself. Moore declined. She said she acted impartially in making her decision.

In South Carolina, criminal domestic violence is a misdemeanor, and arrest warrants must be approved by a magistrate.

Former state prosecutor and U.S. Attorney Pete Strom said it appears state officials did everything they could under the law to obtain a signed arrest warrant.

“If the system has broken down here, it broke down in the judge’s decision,” he said.

The attorney general’s office says it is preparing to close the investigation.

“Is the office disappointed in the outcome?” Plowden asked. “Absolutely. We believe it’s both a sad and a shocking reminder of what a victim of domestic violence faces in court every day.”

Attorney General Henry McMaster has called domestic violence the No. 1 crime problem in South Carolina and fought for tougher domestic violence penalties. He has also begun programs to train law enforcement officials and judges in the complexity of the issue.

Moore took the state’s criminal domestic violence training in April 2003, Plowden said. Sheriff Benson is not on record as having taken the training, but in 2004 he created a full-time domestic violence investigator’s position.

Benson was elected to his second four-year term in November.The couple has been married since 1996 and has a 12-year-old son.

Marcy Benson’s attorney declined to comment.

“Marital difficulties are hard for anyone,” said Michael Hemlepp, the sheriff’s attorney. “They’re especially hard when it gets to the point of going to court, and this man and woman who could have been resolving their differences in private are having to do it on the front page. Frankly, I feel sorry for both of them.”