Dec. Deaths of Indiana Man and 2 Teen Daughters Ruled Murder-Suicide After Investigation

Facebook Lexis and Haley Marvin

After investigating the deaths of a 47-year-old father and his two teenage daughters, authorities in Indiana have concluded that all three died as the result of a murder-suicide.

A statement from the Elkhart County Prosecutor's Office confirms that Haley, 15, and Lexis Marvin, 18, were murdered by their father, Jeffrey Marvin.

The girls were shot to death, officials said. Afterwards, the father turned his gun on himself.

All three bodies were found on Dec. 18, 2020, by police officers who had been dispatched to their Elkhart home after the family had not been seen or heard from for days.

It appears the murder-suicide occurred several days before the bodies were discovered.

"The Homicide Unit has substantially completed its investigation and evidence documented does establish that Mr. Marvin appeared to have a motive, and did kill his two daughters, committing suicide himself thereafter," reads the statement, adding that motive will not be disclosed.

"There was no evidence discovered that suggested any other person was involved, or aware of, the tragic deaths, or that any other person had been in the home during the event or until law enforcement made entry on December 18," it continues. "Accordingly, there does not appear to be any threat of additional violence to the community."

Want to keep up with the latest crime coverage? Sign up for PEOPLE's free True Crime newsletter for breaking crime news, ongoing trial coverage and details of intriguing unsolved cases.

The sisters attended Concord High School in Elkhart.

Marvin shared custody of the girls with his ex-wife.

"These young ladies are profoundly mourned by many, and the assistance provided by their friends, the Concord School community, and their family, was crucial in understanding the circumstances," the statement concludes.

PEOPLE was unable to reach the girls' mother on Wednesday for comment.