SAN FRANCISCO, Calif. -- A man who was fired from a San Francisco social and mental health services agency and returned to fatally shoot a case manager in 2005 was sentenced today to 19 years to life in prison.

Gregory Gray, 58, pleaded guilty in San Francisco Superior Court to second-degree murder on Feb. 26. He admitted shooting Conard House case manager Bruce Franks on May 9, 2005.

Members of Franks' family spoke at today's sentencing hearing, including his wife, Lisa Gershater Franks, who tearfully read a statement in court.

"I want to share my disgust and anger at Mr. Gray for choosing violence," she said. "As a long-time teacher in the Bayview, I spend a great deal of time teaching little ones to cope and to solve problems -- without violence."

Franks' family said he was committed to social justice, loved his family deeply, and strove to help some of the most marginalized residents of San Francisco.

"You sir, are a murderer and a thief," Gershater Franks told Gray. "You have stolen Bruce's remaining potential for helping others and improving his life and those of his son and daughter."

According to prosecutors, Gray, of San Francisco, was fired from Conard House about a year before the shooting, but was seen lurking near the agency that week.

On the morning of the killing, Gray came into the office where Franks, 49, was working alone, and during a struggle, shot Franks with a revolver, prosecutors said.

Another Conard House employee, Kalifa Coulibaly, arrived soon after and was ordered inside the office by Gray, who was now holding a shotgun.

Coulibaly and two passersby were able to disarm Gray until police arrived, but during the struggle, Coulibaly suffered a dislocated shoulder and fractured ankle. Additional shotgun and revolver ammunition were found at the scene.

Gray also pleaded guilty to battery with serious bodily injury for the injuries to Coulibaly.

"You have stolen your own potential for a better life," Gershater Franks told Gray. "Perhaps you felt hopeless, and did not know where to get help. I don't know why you did this terrible act, but I feel you will regret it for the rest of your life."