The Griffith Public Schools, in a response filed Tuesday to a federal lawsuit, disputed arguments that the 14-year-old girls' posts were a joke and that the expulsions violated the students' free-speech rights.

The school district's response includes excerpts from among nearly 70 Facebook comments that were posted by the girls during a two-hour period in January. Those comments included names of at least five people they wanted to kill and discussions of using guns, knives, box cutters and gasoline and filling a bath tub with acid to dissolve a body, according to the court filing.

"These comments and this disturbing conversation posed a `true threat' and two of the threatened students were so fearful of the threats that they missed classes and school," the district's response said.

The district hadn't previously commented on the lawsuit, which was filed in April in U.S. District Court in Hammond.

The American Civil Liberties Union of Indiana, which is representing the girls, argues that Griffith schools officials violated the girls' civil rights by expelling them on the basis of a personal, off-campus conversation.

An ACLU lawyer has said that it was clear the girls were joking because their remarks were accompanied by smiley faces and other emoticons, along with Internet shorthand, such as "LOL."

The girls were suspended and later expelled in January after a classmate's mother alerted officials at Griffith Middle School to the posts. The district said the mother went to school administrators after her daughter refused to attend school because she was afraid of "the graphic threats."

The girls' postings "constituted a substantial disruption to the school environment, thus warranting the school's actions," the district's filing said.

The controversy began after school on the afternoon of Jan. 24, when one of the girls posted a Facebook status update "concerning her disdain for cutting herself while shaving her legs," according to court documents.

The update was only visible to that particular girl's Facebook friends. Then the three girls began commenting on the status update from their personal home computers, allegedly joking about various topics in some 70 comments that were posted in the span of two hours, Rose said earlier this year in an ABC News report.