Military police did little in response to a sexual assault complaint from an Air Force master sergeant who later took her life, the Criminal Investigation Command said Wednesday.

The victim’s family believes the military police neglected to carry out a thorough investigation when she filed the complaint at her base March 2, when it happened. She was found dead May 22.

“Police initially found the perpetrator, Jang, who texted her twice after the incident, which they thought was an apology,” said a senior official at the command, which oversees the military police. Jang threatened to kill her in the text message if she did not “let it go,” the official said.

Jang was indicted Monday on charges of sexually assaulting the master sergeant and of threatening to harm her if she testified or asked others to testify against him. Another warrant officer senior to the victim is also facing indictment for allegedly sexually assaulting her a year ago.

After the Defense Ministry took over the case from the Air Force, it brought in civilian advisers to guarantee what it has called a thorough and transparent investigation. But the military is still accused of turning the other way when its members are accused of sex crimes.

The military has so far questioned 13 service members in the investigation, including a military prosecutor and a public defender appointed to represent the victim. The prosecutor and the public defender are accused of not doing their jobs by promptly working to establish a sexual assault case.

But the investigation has yet to bring charges against any of the military police who were the first line of help when the victim reached out. An initial investigation found that they ignored incriminating evidence against the accused man.

“We need something to nail them down to specific violations of laws in order to press criminal charges. We’re closely working with the civilian committee on that,” the senior official said, referring to the committee set up to advise on the investigation. The committee will look at the issue this week, he added.

A senior Defense Ministry official reiterated that everyone involved in suppressing evidence or blackmailing witnesses would face strict punishment, saying, “They will receive penalties -- whether from the court or from the ministry.”

By Choi Si-young (siyoungchoi@heraldcorp.com)