The shocking and disturbing case of Antonio Lasaga, a former Yale geology professor and Saybrook College master, essentially came to an end Friday when a Connecticut Superior Court judge sentenced the child molester and pornographer to 20 years in prison. That sentence will be served concurrently with a 15-year federal term that Lasaga received last week.

With Lasaga finally headed to prison — pending an appeal from his attorney — it is appropriate to reflect on the troubling legacy he has left behind.

From its beginnings in late 1998 to the sentences pronounced last week, Lasaga’s case was as stunning as it was perverse. To almost all who knew him, Lasaga seemed an intelligent, compassionate and friendly man. His abilities as a scientist were unquestionably world-class, and his personal skills were good enough to earn him the Saybrook mastership.

It was in that context that the Yale community discovered Lasaga had downloaded child pornography and sexually abused a boy he mentored through a city program. FBI agents searched Lasaga’s house on Nov. 6, 1998, and Yale College Dean Richard Brodhead announced the master’s resignation the same day.

The next three and a half years were agonizing for all involved. Lasaga was arrested and charged with state and federal crimes in the months after the FBI investigation, and he eventually pleaded guilty to the federal charges and no contest to the state charges. After dragging his feet for a year and a half, Yale President Richard Levin convoked the University Tribunal in April 2000 to consider revoking Lasaga’s tenure. It took him nearly another year to fire Lasaga after the tribunal made its decision and the Yale Corporation considered Lasaga’s appeal.

The administration, like Lasaga’s students, colleagues, family and friends, seemed mired in a state of disbelief. Even as late as Friday, fellow geologists told the court that Lasaga couldn’t have had time to look at all the obscene pictures because his work kept him too busy. The sad truth is that state prosecutor David Strollo was right when he said he had “never heard comments so disconnected from reality.”

As disturbing as it is, both the Yale community and the scientific world must finally accept the reality that Lasaga is an extremely sick man. It has been debated whether he should be allowed to publish his research in scientific journals. The argument seems almost irrelevant, as Lasaga’s crimes will forever hover over any work he might contribute to science.

By committing such unspeakable acts, Lasaga betrayed his responsibility as a professor, master and mentor, and he robbed the entire community of its sense of security and trust in what is supposed to be a nurturing, learning environment.

We hope Lasaga’s imprisonment will mend some of the emotional wounds he inflicted on those around him and, most terribly, on his victim. But in the end, we can only pray that time will help wash away the legacy he leaves behind — one of suspicion and doubt that will not soon be forgotten on this college campus or any other.