The 20-year-old man who confessed to killing four Bucks County men in a span of three days reportedly told police it wasn’t the first time.

According to a report in the New York Times, sources with knowledge of the investigation said that in DiNardo’s murder confession last Thursday, the suspect admitted to killing two other people in Philadelphia when he was 15.

In addition, a former friend told the newspaper that DiNardo had assaulted two strangers at a mall, also at age 15, punching two men who were reportedly talking to his then-girlfriend.

“Cosmo was crazy,” said Amber Peters, 20. “He’s been talking about killing people since he was 14.”

It is not known if police are treating the reported confession as evidence of more deaths or the exaggerated claims of a young man diagnosed with a mental illness.

Meanwhile, the family of a 22-year-old man who went missing in same area where the four young men were murdered is worried about him.

Timothy Caesar was last seen on June 1 at a 7-11 in Bucks County, and no one in his family has heard from him since.

Timothy’s mother Karen Gilbert told CrimeOnline that her son had become increasingly paranoid in the days leading up to his disappearance and said the night before he was last seen that he believed people were out to hurt him. He was visiting his mother in Northeast Philadelphia when he went missing, he was living with an aunt at the time, and had lived with multiple relatives over the years. Gilbert said he has a tendency to be secretive.

She said she remembers walking into his bedroom not long before his disappearance and seeing what looked like the face of a dark-haired man on his computer, in a possible Skype or FaceTime chat. She said she could not be sure of what she was looking at, and that Timothy quickly slammed the computer shut. She also said that she can’t access the mobile device he was using at the time of his disappearance because another family member, frustrated and concerned about his paranoid behavior, threw the device on the floor and it broke.

The precise circumstances of Timothy’s disappearance are not entirely clear, but Gilbert said she drove Timothy, at his request, to a 7-11 in Croyden, Bucks County, just a few miles from the Soldedad Township farmland property where the four young men were murdered.

She told the Philadelphia Inquirer that Timothy asked to go into the store alone and that he wanted to walk home. She agreed, but said she wanted to follow him, so she turned her car around and watched for him. She said she believes she saw her son get into a white car driven by a man with black hair.

Both Gilbert and her husband, Timothy’s stepfather, said they were certain Timothy would not have been involved in buying or selling drugs.

Investigators told the Philadelphia Inquirer that there is no known connection between Caesar and DiNardo or Kratz.

“At this time there is no indication that his [Ceaser’s] disappearance is tied to the murders of the four men in Solebury, or to Mr. DiNardo or Mr. Kratz,” Bucks County District Attorney Matthew Weintraub told the newspaper.

For her part, Gilbert is holding on to the hope that her son left on his own and will return when he feels it is safe. But she told CrimeOnline she had not ruled out the possibility that something had happened to him, and said she and her husband have searched a nearby river for clues.

On Sunday night, about 1,500 people gathered for a vigil honoring the victims of the horrific quadruple murder.

Friends and family of Jimi Patrick, 19, of Mark P. Sturgis, 22, of Pennsburg; Thomas C. Meo, 21, of Plumstead; and Dean A. Finocchiaro, 19, of Middletown Township, shared memories, photos, and their disbelief that these well-liked young men were brutally murdered.

“I can’t believe he’s gone,”  Kaitlyn Masone, a 19-year-old childhood friend of Patrick’s, told the Philadelphia Inquirer.