There's been a second arrest in the San Francisco Police Department's alleged rape/racist text scandal: This time it's the Lieutenant who oversaw the alleged rapist/racist texter who now faces charges of obstructing the investigation into his underling's alleged sexual assault.

The clouds of witness have been gathering over former Taraval Station Lieutenant Curtis Liu since August, 2015, when a woman being treated at San Francisco General Hospital for injuries from an alleged sexual assault said then-officer Jason Lai was the man responsible.

By the end of August, an internal affairs investigation revealed that "a fellow officer at the Taraval Station and friend of the accused, compromised the investigation" and that he “intentionally interfered with a felony sexual assault investigation both by lying to the officers investigating the incident and by contacting the suspect directly to inform him of the progress of the investigation," a search warrant used to seize both officer's phones.

By March of this year, the "fellow officer" was identified as former Lieutenant Curtis Liu, who retired as the investigation into his activities continued. Lai was arrested — not for the rape, as the District Attorney's office deemed the evidence insufficient — but for two misdemeanor counts of unlawful possession of local criminal offender history Information and four misdemeanor counts of misuse of confidential Department of Motor Vehicles Information.

And the investigation into Liu continued, with the DA's office announcing in March that based on evidence from their seized cell phones, Liu and Lai had exchanged texts characterized by the DA as racist, homophobic, and bigoted.

We got a look at Lai's side of the conversation (as well as a number of his other remarks) Tuesday, when Public Defender Jeff Adachi released page upon page of Lai's vile texted remarks. Just a day after that, the DA's office announced in a statement, Liu was arrested "charged with obstructing a rape investigation involving another San Francisco Police Officer by making false and misleading statements and withholding key information from officers who were investigating the rape allegations."

According to the DA's office, after the rape report was made "Then-Lieutenant Liu contacted a San Francisco Police Officer who worked at his station, and who had the same name as the reported rapist. Lieutenant Liu discussed the allegations with the Officer, and the Officer provided Lieutenant Liu with information that confirmed that the Officer was, in fact, the person that the rape victim was referring to."

"Instead of reporting this information to his fellow officers, Liu engaged in a series of actions designed to keep the investigation from focusing on the Officer," The DA's office alleges. "These actions included lying to his subordinates and superior officers about the fact that he had contacted the suspect-Officer, and permitting the police report regarding the rape to be filed with the suspect listed as 'unknown,' when Lieutenant Liu knew that the proper suspect was the Officer."

“A willingness to cover up allegations of a crime as serious as rape is not an acceptable quality in any police officer,” District Attorney George Gascón said via press release.

“But the fact that such a void of principle was demonstrated by a leader makes this behavior that much more concerning.”

A statement sent Wednesday night by SFPD confirms the details of the case, and adds that it was SFPD's Internal Affairs investigators who made yesterday's arrest and booked Liu into San Francisco County Jail.

The Associated Press reports that Liu has retained lawyer Tony Brass to defend him, but an effort to reach Brass to confirm this was unsuccessful as of publication time. Brass also defended at least two of the SFPD officers in the department's last racist texting scandal in 2015, so it's safe to assume that he knows his way around a disgraced cop case.

Additional lawyers who specialize in disgraced law enforcement officers might soon find themselves with more on their plate, as Lai and Liu aren't the only cops under scrutiny in this case. Also involved in this newest texting scandal are former Officer Keith Ybarreta, who along with Lai and Liu left the department over the course of the investigation, and a fourth, unnamed officer who the Chron says is "awaiting a disciplinary hearing in front of the Police Commission and faces possible termination." That mystery man was suspended as of October, 2015, SFPD Chief Greg Suhr says, but obviously there's at least one more shoe left to drop.

Liu, who according to a San Francisco Sheriff's Department spokesperson has "bonded out" and is no longer in custody, has been "charged with one count of violating California Penal Code Section 118.1 (Making a False Statement in a Police Report), a felony, and two counts of violating California Penal Code Section 148(a)(1) (Delaying or Obstructing a Peace Officer), both misdemeanors," the DA's office says. The date of his arraignment has yet to be set.

Previously: Seven Months After Alleged Sexual Assault, SFPD Officer To Finally Face Some Music
More Racist SFPD Texts Were Uncovered During Sexual Assault Investigation Of Officer
Newest Batch Of Racist SFPD Texts Might Be Worse Than The Last One, 207 Cases Under Scrutiny