After killing his 22-year-old fiancée Gabby Petito, Brian Laundrie apparently knew he was going to commit only either of these two things - surrender to the police or kill himself.

According to a friend's account, when he fled his parents' house in fear, he was contemplating turning himself over to the authorities. Unfortunately, he decided on the other option.

When he heard his mother's name mentioned in a conversation, Brian's mind became made up to commit suicide, a friend of the Laundrie family tells the The Sun.

The friend, who asked to remain unnamed, told The Sun that he was driven to leave his parents' North Port, Florida, house on September 13 because of the media attention, the irate demonstrators, and the phone call.

"He was contemplating everything," the friend said. "He promised his parents he would wait until they issue an arrest warrant and then turn himself in and fight the case," the insider added. "But that whole day was awful."

The call that sealed Brian's fate was revealed by the source, who said that he was terrified the police would arrest his mother.

"The police were talking to Steven (Bertolino, the Laundries' lawyer), the media stuff started. Steven was on speaker phone, and Brian heard him say police might arrest his mom," the friend stated.

This prompted Brian to leave, despite his father telling him to cool his head first. He told his dad he was merely getting some fresh air and clear his thoughts, which the father did not find odd because he usually does that anyway. Brian also told his parents he was going on a solo hike in the Carlton Reserve near their home. He probably knew he would be committing suicide and no longer see his parents again, the friend said.

One of Brian's friends described the day Brian left as "a rough day, and his mind was made up," and revealed that "the bottom line though is that his mom blames herself."

The source claims that Brian's father, Christopher, is "on the verge of collapse." This is what hurts Brian's friend the most, seeing the dad falling apart when none of this was his fault. He described Brian's father as being a great one.

On the 20th of October, a body was found not far from the Carlton Reserve that belonged to Brian. He confessed to the murder of Gabby in a notepad he left behind.

After Brian left his parents' house, Gabby's body was located in Wyoming just a few days later. Autopsy results showed she was strangled to death and had "blunt-force injuries to the head and neck."

Unfortunately, even if Brian Laundrie did not want his mom arrested, this is probably now on the cards.

Gabby Petito's parents have recently filed a $100k lawsuit against the Laundrie family.

This summer, Gabby's parents will be able to present their case in court. The court has scheduled a required meeting for June 30 at 1:30 PM in Sarasota County Court.