A Westbrook woman who is accused of allowing her boyfriend to sexually assault a 14-year-old relative with developmental disabilities has been indicted by a grand jury on a half-dozen related charges.

Holly Morrison, 34, of 110 Brown St., is scheduled to be arraigned June 5 in Cumberland County Unified Criminal Court on three counts of gross sexual assault, a felony punishable by as much as 30 years in prison, and three misdemeanor counts of endangering the welfare of a child.

Morrison, now free on $500 cash bail, is accused of watching her boyfriend, Donald Cass, use objects to assault the girl at least three times last fall, according to court records.

Westbrook police were first alerted by school officials on Nov. 14, after the girl told friends and a counselor that she had been assaulted by Cass multiple times. The girl also told officials that Morrison insisted she get in bed naked with the adult couple and shower with them, according to a report by Westbrook Detective Steve Crocker.

Cass, 59, of 57 Towle Ave. in Auburn, was arrested in the case last year and pleaded guilty to two counts of gross sexual assault.

Cass, a former reserve police officer in Auburn, was sentenced on Feb. 24 to serve four years of an eight-year prison sentence, with the balance suspended for a four-year probation term.

It is unclear why Morrison was indicted so long after Cass was sentenced. The Cumberland County District Attorney’s Office announced Morrison’s indictment Friday, and her case file was made available in court Monday.

The prosecutor in the case, Assistant District Attorney Michael Madigan, could not be reached for comment. Westbrook police did not return phone messages left Friday and Monday.

Morrison told police that she met Cass at a “swingers party” and they participated together in swingers’ events.

Cass, who is married, told police that he would visit Morrison’s home on weekends while telling his wife that he was going on hunting or fishing trips, according to court records.

As a condition of bail, Morrison was ordered to have no contact with Cass or the victim in the case.

Scott Dolan can be contacted at 791-6304 or at:

sdolan@pressherald.com

Twitter: @scottddolan