Hearing a knock at the Motel 6 door, a prostitute wearing a black catsuit answered, $20 bills stashed in her cleavage. In the bathroom, Sunnyvale police officers found a veteran Menlo Park police detective wearing nothing.

End of his career? Nope.

Officer Jeffrey Vasquez, 48, returned to duty in the Menlo Park Police Department late last year, following an internal affairs investigation triggered by the bust. He had also been charged with misdemeanor solicitation by the Santa Clara County District Attorney. What internal sanctions he faced remains unknown; the state's confidentiality laws prevent discovery of penalties levied by his employer.

The leak

Under California law, internal affairs investigations -- even the fact that an investigation has occurred -- are confidential personnel matters. So are complaints of misconduct and police disciplinary records.

But the investigation came to light anyway more than a year later. On Oct. 17, 2012, Menlo Park City Manager Alex McIntyre sat talking about city business with his predecessor, Glen Rojas, at a communal table near the bar at the Menlo Hub, a Menlo Park restaurant. Their conversation carried to an Almanac reporter sitting at the other end of the same table.

Part of their discussion involved the city's binding arbitration policy, invoked when a police officer appeals a disciplinary penalty after failing to convince city management to reverse it. Apparently the city "lost royally" during arbitration, Mr. McIntyre said, forcing Menlo Park to reinstate the officer. The city manager said he told the council that paying the officer to leave instead of returning to work would be "a million dollar check."

He expressed frustration that some members of the City Council wanted to discuss the matter publicly despite regulations prohibiting disclosure.

Without naming Officer Vasquez, the city manager mentioned the officer's length of service and gender. Only two current officers matched the description; a painstaking search of employment data, police logs and court records led the Almanac to a Santa Clara County Superior Court file that detailed the case against the officer.

"You overheard a conversation between two colleagues," Mr. McIntyre told the Almanac during an interview in January. He said he didn't remember precisely what he said at the Hub, and stated that it's not unusual for a city manager to consult his predecessor.

As for the case itself: "(City Attorney) Bill McClure said I can't say anything."

Officer Vasquez told the Almanac he'd been ordered not to talk about it by the interim police chief. At an hourly rate of $52.40, his annual base wage is approximately $109,004. Should he retire at age 50 with at least 25 years of service, he'd receive 75 percent of his final salary as a pension; that increases to 90 percent if he retires after 30 years.

The officer's attorney did not respond to requests for comment. Neither did Bryan Roberts, who was serving as Menlo Park police chief at the time of the incident.

The motel

Jeffrey Vasquez jeopardized his 24-year career with the Menlo Park Police Department when he went to the wrong place at the wrong time on Feb. 18, 2011.

According to court documents, a Sunnyvale police officer acting on a tip was watching a motel room for signs of 32-year-old Natalia Ramirez, who had two outstanding bench warrants. He knocked on the door. Once inside, the officer asked Ms. Ramirez what was going on.

"She replied that it was what it looked like. I asked her if it was prostitution, she replied by saying yes," the police report stated. Her male companion did not reveal himself as a fellow law enforcement officer until a check of his driver's license alerted the Sunnyvale police that he was.

Detective Vasquez was in Sunnyvale to serve a subpoena related to a Menlo Park sexual assault case, he told the officers, "and this was not the first time he had solicited a prostitute for sex," according to the filing. Upon learning that the target of the subpoena wouldn't be home until later, the report states the detective said, "I had an hour to kill" so he called "My Redbook," a site listing local escorts and their phone numbers.

Ms. Ramirez confirmed that she advertised on Redbook and said that Detective Vasquez had called her, asking to come over later, according to the Sunnyvale police report. She didn't remember what name he had used.

The Menlo Park police officer "admitted that he was there for sex" and that he had found her on Redbook. They hadn't engaged in sexual activity before Sunnyvale police arrived or discussed specific prices or services, according to the report.

Asked why he didn't immediately identify himself as a police officer, Detective Vasquez reportedly responded, "I don't want to be a dick and ask for preferential treatment."

Senior officers from Sunnyvale and Menlo Park arrived on the scene after a series of calls -- standard procedure when an incident involves a fellow officer, according to law enforcement sources. Capt. Carl Rushmeyer of Sunnyvale showed up, then Watch Commander Tim Brackett and Sgt. Matt Bacon of Internal Affairs, both from Menlo Park.

Ms. Ramirez, who has a criminal record for drug possession and prostitution, was arrested on the bench warrants. The report noted that Sunnyvale police turned a "distraught" Detective Vasquez over to his Menlo Park colleagues and forwarded the case to the district attorney.

Charged with misdemeanor solicitation, Officer Vasquez hired Redwood City attorney William Rapoport to handle the case and pleaded not guilty in June 2011.

A month later -- on July 11 -- the prosecution asked to dismiss the case. The problem? Prosecutors were notified the day of Ms. Ramirez's trial that the officer who had interviewed her was unavailable to testify. According to Deputy District Attorney Rob Baker, who supervised the case, the officer was caring for his wife as she endured a life-threatening medical crisis. A Sunnyvale officer confirmed the circumstances related to the dismissal to the Almanac and said his department had hoped the case could have gone forward.

"I wanted to prosecute the case, that's the reason we charged it," Mr. Baker said. "But in light of the (misdemeanor) charges, we didn't feel it appropriate to force the cop to come to court when his wife was going through something that serious."

Losing a key witness left the case against both Ms. Ramirez and Officer Vasquez dead in the water. "We couldn't prove the case against the cop because the (officer) who actually observed him in the room with the prostitute wasn't available," Mr. Baker said.

The court would regard the confessions recorded in the police report as inadmissible hearsay, he explained, without the testimony of the officer who took the statement.

Compounding their dilemma, Ms. Ramirez had not waived her time to a speedy trial. Mr. Baker said, "We literally had to go to trial on that day or within 10 days."

His team looked for workaround strategies to no avail. They concluded that ultimately they weren't going to be able to use Ms. Ramirez's statement. "What's the jury going to think when the primary officer doesn't show up to testify? If I was to dismiss the case against her, his defense attorney would then know we couldn't prove the case against him," Mr. Baker said. A pre-trial conference for the charge against Officer Vasquez had been set for the same day as Ms. Ramirez's trial.

In the end they asked the court to dismiss the case for lack of evidence. "With misdemeanors, you only get one bite at the apple. The case gets dismissed, and that's it," Mr. Baker said. "Had this been felony conduct, we could have dismissed and then refiled it."

The ties that bind

The dismissal of the criminal case sheds some light on how Officer Vasquez was able to return to duty. The city of Menlo Park's administrative mechanisms also contributed to his reinstatement.

Personnel procedures separate criminal proceedings from administrative hearings, according to the city's human resources director, Gina Donnelly. "You have to be careful not to impede a criminal investigation," she said.

As with all other city employees that the Almanac questioned about the case, Ms. Donnelly said she couldn't talk about Mr. Vasquez and could answer only general questions about the disciplinary process.

"An employer can't take disciplinary action based solely on an arrest. It depends on what they're arrested for, if there's a nexus to their employment and whether there's a conviction. All city employees are held to a very high ethical standard, and police officers are held to an even higher standard."

The standard of proof for an administrative hearing is lower than that for a criminal trial. "It's 'more likely than not,' similar to the standard in a civil case," Ms. Donnelly said, as opposed to "beyond a reasonable doubt" in a criminal case. But while court proceedings generate public records, administrative hearings don't.

Three levels of discipline exist: a letter of reprimand, suspension, and the most serious, dismissal. An officer may appeal the decision within the department and then to the city manager, Ms. Donnelly said. If challenged again, the case goes to binding arbitration.

Binding arbitration is written into the city's contract with the police unions, according to City Attorney Bill McClure. The contract spells out the steps: The union and city first try to agree on an arbitrator. If they don't, the State Mediation & Conciliation Service supplies a list of five names, and the union and the city take turns eliminating names until one remains; that person then serves as arbitrator.

No single set of guidelines applies to the criteria an arbitrator uses to reach a decision, Ms. Donnelly said.

The contract states: "The award of the arbitrator shall be final and binding." In other words, that person can overrule whatever disciplinary decision the city made.

Many jurisdictions in California, including San Jose and Palo Alto, use binding arbitration. Sources familiar with the process said it makes removing a problem police officer nearly impossible.

Credibility under oath

How does a troubled past affect an officer's future credibility in court? In 1963 the U.S. Supreme Court in Brady v. Maryland ruled that prosecutors must disclose exculpatory evidence to the defense, including misconduct by a police officer who might be called as a witness in a case if that misconduct could discredit or impeach the officer's testimony.

As in other jurisdictions, San Mateo County District Attorney Steve Wagstaffe said his office keeps a "Brady list" of police officers charged or convicted of an offense, and discloses that information to the defense when the officer will testify while facing charges or serving probation. He said some crimes, such as misdemeanor drunk driving, allow the removal of the officer from the list after he completes probation.

Other crimes, such as a moral turpitude offense or one related to credibility, such as filing a false report, keeps the officer on the list in perpetuity. The Brady list is not public record; the information "is accessible only to our attorneys in handling their cases," Mr. Wagstaffe said.

A police officer charged with soliciting a prostitute may not make the list. Mr. Wagstaffe said that case law considers solicitation by the prostitute as an act of moral turpitude, but wasn't sure whether that held true for the john. "Doesn't seem like it should be different, but the law is a strange thing in so many distinctions it draws."

The district attorney, having never seen a case on that point, said the question would require some research.