Supervisors suspected him for years but Anthony Rollins, a police officer now convicted of a string of sexual assaults, was allowed to stay on the streets, spending long, unsupervised stretches alone in his patrol car. Complaints about sexual misconduct piled up. Investigations were launched. But somehow, in an organization filled with people trained to spot predators, Rollins slipped by.

We should be looking at why.

There's been a criminal trial. Rollins faces life in prison. Nine women have sued the municipality in civil court. One of them settled for a tidy sum. The city stands to lose millions more. When you have an officer with a history of sexual misconduct investigations assaulting people on the job, there is no question that the leadership of the Anchorage Police Department failed to give him the supervision he needed, and that the internal system for investigating and disciplining officers failed.

You would think, looking at this stark set of facts, that a mayor or a police chief would see this as an opportunity to call for an external investigation, to figure out what went wrong and fix it. But as far as I can tell, that's not happening. And that's disturbing.

Look through the pile of internal police documents released as part of the civil suits and a clear pattern of behavior emerges. As time passes, police recognize that Rollins is a risk. But Rollins stays on the streets.

The set of internal APD documents filed in court so far is incomplete. But based on what's there, here's a timeline of at least some of Rollins' questionable activities:

2001: APD investigates a rumor that Rollins is having sex on the job. Rollins admits to visiting a woman while on duty but denies the sex. The investigation goes nowhere.

2003: A prostitute tells police Rollins made vulgar statements and threatened to arrest her if she didn't perform sexual favors.

APD, with help from the FBI, launches an investigation. Using surveillance and an undercover agent posing as a prostitute, they launch a sting. Rollins contacts the woman and does not follow "APD protocol." She describes his behavior as "flirtatious." The operation is suspended until the next year.

2004: The sting resumes. Using surveillance from the air and a GPS transmitter installed on Rollins' car, police see that he is spending time on duty at a residence. When confronted, Rollins admits to having an affair with a woman from his church, including at least 20 encounters while he was on duty.

One of the investigating officers concludes: "His conduct would have a tendency to destroy public respect for himself and the Anchorage Police Department if the facts of this investigation were known."

Rollins is demoted and given a drop in pay. (Walt Monegan is chief at the time.)

2005: Lt. Paul Honeman walks in on Rollins, lying on a desk, in the Public Affairs office at APD. Honeman sees the feet and hair of what seems to be a woman underneath. Honeman leaves. When questioned about it later, Rollins denies a woman was in the office and says he was sleeping. Honeman reports the incident but it's unclear how the investigation concluded.

2007: Sgt. Roy LeBlanc takes the report of a woman who was arrested for drunk driving. The woman says Rollins made sexual comments to her as he drove her to jail. Police investigate, including calling "10 percent" of the women Rollins had arrested in the last year. None of these women reports any unusual comments. The investigation fails to substantiate the complaint.

2008: Police get a report that Rollins is "engaging in a sexual relationship while on duty." Another officer, Ray Jennings, becomes suspicious after seeing Rollins and a woman at the Muldoon Substation. The same officer recalls an earlier day when he saw Rollins having a "social visit" with a woman "hanging in his window" in Mountain View.

Okay, so stop right there. That's almost one serious sexual complaint a year. At the very least, doesn't it appear that Rollins has done enough to breach the police code of conduct? I asked APD for a copy of its conduct policy. I was told by Sgt. Jim Bucher, who works in Internal Affairs, that the department's standard of conduct isn't public information. (He was so nervous when I called him, he recorded our conversation.)

A few days later, the city released the code of conduct to all media. It makes repeated mention of the requirement that police "display good moral character" both on and off duty. The reputation of the department is paramount.

"Honest in thought and deed in both my personal and official life, I will be exemplary in obeying the law and the regulations of my department," it reads.

Violation of this code could be grounds for firing. I'm no expert, but looking at Rollins' history, and the fact that he had an affair while on duty, I have to ask: Why wasn't he fired in 2004?

Anyway, back to the timeline. In July 2008, LeBlanc files an affidavit for a warrant to monitor and record Rollins in his police car. It's clear he suspects Rollins of something serious.

"During his police career with the Anchorage Police Department, Officer Rollins has been the subject of numerous complaints relating to accusations of behavior of a sexual nature. Collectively, these accusations suggest a pattern of behavior which poses a risk to the public," LeBlanc's affidavit says.

He also mentions that Rollins has been assigned as a day shift patrol officer, a position that affords Rollins "significant discretional use of his time and activities without constant direct supervision."

LeBlanc's findings would have been shared with then-Chief Rob Heun. I don't know what LeBlanc concluded but I do know that Rollins stayed on the job. In February 2009, Heun even gave Rollins a letter of commendation for his work arresting drunk drivers.

"Tony, your effort helped save lives and has made Anchorage a safer place to live ... Your hard work ... demonstrate(s) that the community profits and prospers because of our employees. ... Keep up the great work."

I called Heun, now the federal U.S. marshal for Alaska. I wanted to ask him why LeBlanc's warning wasn't enough for APD to keep Rollins off the street. He said he couldn't comment.

After LeBlanc wrote his affidavit, Rollins assaulted at least four women. Another woman said he used his position as a police officer to visit her at an inpatient drug treatment center, where they had sex.

So what we have is a police officer who mixed sex with work, got caught doing it, and kept doing it. At some point he became a predator. His bosses suspected this but kept him on. He harmed women and, just as bad, he harmed the public's trust in the police department. Rollins committed the crime but the system gave him the power to do what he did. The system needs to be examined.

I called APD because I wanted to know if there was going to be any kind of look at what went wrong in the department's handling of Rollins. No one there would answer the question. They directed me to city attorney Dennis Wheeler.

I called Wheeler. I called the city manager. I called the mayor's office. Days passed. No one returned my calls. Then a formal statement came out.

"In the criminal trial, the Anchorage Police Department produced evidence showing that it acted quickly to get Mr. Rollins off the streets when a sexual assault was first reported ...," it read "... The Municipality is not aware of evidence that concludes someone who has had a consensual sexual encounter (an ongoing affair) while on the job is likely or highly likely to commit sexual assaults."

There was no mention of a review.

As best I can tell, the burden of figuring out how a predator ended up in a patrol car for years -- even as his bosses suspected he was a danger to the public -- is carried only by his victims, who are having to sue to get answers. That is not enough. Until the city takes an objective look at what happened with Rollins, holds people accountable and changes procedures that failed, we have no assurance it won't happen again.