BOSTON -- A former Maynard firefighter pleaded guilty Tuesday to sexually assaulting a family friend.

Anthony "Toby" Tyler, 46, pleaded guilty in Woburn Superior Court to a charge of indecent assault and battery on a person 14 years or older.

Middlesex Superior Court Judge Jane Haggerty sentenced Tyler to three years in state prison. Tyler will serve that sentence following the completion of his current three-year state prison term for a sexual assault conviction against another victim. He pleaded guilty to those charges on March 21.

"Anthony Tyler violated the innate trust of a close family friend to commit this disturbing act," District Attorney Gerry Leone said. "He has now been convicted in two separate cases and will serve a total of six years in state prison for those crimes. He also will remain a convicted sex offender for the rest of his life."

Tyler was a close family friend of the victim and would frequently visit his home in Maynard, police said. Officials said Tyler began to inappropriately touch the victim when he was a child. The assaults soon escalated and continued throughout elementary school and high school, up to when the victim was approximately 25 years old. The indecent assault and battery that Tyler pleaded guilty to occurred in 2002 when the victim was 31 years old.

Tyler was indicted by a Middlesex Grand Jury on Jan. 25, 2007, on charges of rape and indecent assault and battery on a person 14 or over. He was arraigned on those charges on Feb. 6, 2007, in Middlesex Superior Court. Tyler was released on his own recognizance and ordered to stay away from and have no contact with the victim or his family.

Tyler was previously indicted by a Middlesex Grand Jury on Oct. 24, 2006, in connection with the alleged sexual abuse of a boy that occurred when the victim was between the ages of 14 and 17 years old. Tyler was charged with three counts of indecent assault and battery on a person 14 or over.