A Dorchester District Court probation officer who had just been indicted for the rape and assault of a woman in his charge died Tuesday afternoon in a car crash in Randolph. William Averill, 50, of West Roxbury was due to be arraigned in Suffolk Superior Court on Wednesday after a Suffolk County brand jury indicted him for three coins each of rape and indecent assault and battery and one count of assault with intent to rape.

Authorities say Averill had been on administrative leave from his job as a probation officer since an investigation began earlier this year.

Officials say that on Jan. 5, the victim, a woman in her 20s on a one-year probation term for larceny and stolen property, reported to the court’s probation office as required by her sentencing:

“Averill allegedly led her into his office, where he began to touch and kiss her. She told him to stop and he did. However, later in the meeting, Averill allegedly closed the blinds in his office and sexually assaulted the victim.”

Authorities say that after leaving the courthouse, the victim called a relative about the attack.

“Criminalists in the Boston Police Crime Lab were able to develop a DNA profile from evidence collected during that investigation,” officials said in a statement. “Further testing by Massachusetts State Police criminalists showed that the profile matched a DNA sample provided by Averill – and excluded 99.92 percent of the male population as possible contributors.”

Averill was killed when his car struck a bridge abutment on Route 28 in Randolph just before 4 p.m., according to the Boston Globe.