Authorities in Indiana said a 20-year-old man fatally shot his mother, father and teenage sister before killing himself.

The police received a distress call Monday night from someone about shots being fired inside a home on West Cook Road. When first responders arrived at the scene, they found four people dead.

The shooter has been identified as Samuel Long by the Allen County Coroner’s Office, while the others were 50-year-old Mark Long, 45-year-old Lisa Long and 15-year-old Mahala Long, according to NBC News.

Authorities still do not know what happened in the moments leading up to the shooting, and who exactly was in the house. Mark, Lisa and Mahala died by gunshot wounds, and their deaths were ruled a homicide, the coroner's office said, according to WPTA21.

The police said an elderly woman was also in the house, but in a different part when the shooting happened. She was able to escape and call for help. Her relation to the rest of the family was not known.

Allen County Sheriff’s Department Chief Deputy Troy Hershberger said the preliminary investigation showed many legally obtained weapons were present in the home. Hershberger also said there were no signs of forced entry into the home.

The motive for the shooting was not clear. Those involved in the triple murder-suicide did not have any criminal history. An investigation is currently underway into the killings and suicide.

A man allegedly shot his wife and her child before turning the gun on himself at their home in Arkansas in October. Two juveniles told the police they had heard gunshots coming from inside the house. Upon entering the house, the officers found the bodies of two adults and a child. The adult victims have been identified as Gabriel Brown and Nakina Gilmer-Brown. The child's identity was not made public. It was not clear if the man was the child's father. Two other children who lived in the house were able to escape before the shooting, local media reported at the time.

If you have thoughts of suicide, confidential help is available for free at the National Suicide Prevention Lifeline. Call 1-800-273-8255. The line is available 24 hours, every day.

Crime scene police line | Representational Image
Crime scene police line | Representational Image GETTY IMAGES / SCOTT OLSON