A probable cause affidavit filed in the murder case against a North Vernon man alleges the victim was savagely beaten over a disagreement about missing keys.

That’s what one witness told investigators he saw when Brian K. Kirby, 52, of North Vernon was last seen alive March 27, according to a probable cause affidavit filed Thursday in Jennings Circuit Court.

Alan J. Marantos, 34, of North Vernon, now being held at the Jackson County Jail in Brownstown, was arrested Thursday on charges of murder, robbery (Level 2 felony), aggravated battery (Level 3 felony), abuse of a corpse (Level 6 felony), obstruction of justice (Level 6 felony) and intimidation (Class A misdemeanor) in connection with Kirby’s death.

Investigators believe Kirby’s body was first burned before parts of the charred remains were discarded in multiple locations around Jennings County, according to Indiana State Police investigators.

After Kirby was discovered missing, one of his three daughters talked with a woman residing on Primshire Court who had allowed Marantos and Kirby to occasionally stay in her home, the affidavit stated.

It was the night of his disappearance that an intoxicated Kirby came to the house and got into an argument with Marantos about lost keys, the affidavit states. One witness later told police Kirby had the keys in his pocket but was likely too intoxicated to realize it.

While the woman who lived at the Primshire Court address said she saw Marantos punch Kirby once, the defendant later denied that claim to police. She also told police she last saw Kirby walking away from her home at 11 p.m. on the night he disappeared.

However, another witness who also stayed at the Primshire Court home interviewed by investigators provided more information.

The witness told police he saw Marantos throw the victim up against a refrigerator before physically tossing him out of the house. About a week later, the witness also told investigators the defendant threw the victim against a sink and down on a hallway floor before forcing him outside.

After admitting he was afraid of the defendant, the witness said he felt more comfortable giving investigators more details after Marantos was jailed on unrelated charges.

He told police he saw Marantos throw Kirby over a porch railing before he also got down in the yard and began hitting him repeatedly, the affidavit said. According to the witness, Marantos’ hands were covered with blood after the assault, and Kirby, whose entire face had swelled up, did not move, the affidavit stated.

Moments later, the witness said he saw the defendant put Kirby over his shoulder and place him in the pickup truck he was driving. Police believe it was a dark-colored Chevrolet Avalanche owned by the woman on Primshire Court.

Information in the affidavit also came from a co-worker and relative of Marantos who said Marantos showed up at his home sometime before midnight that same night, the affidavit states.

According to the co-worker’s fiance, who was also in the house, Marantos was “frantic,” “talking 100 miles per hour” and “talking in circles” when he showed up. Both she and the co-worker told police they thought he was high on methamphetamine, the affidavit stated.

Marantos was shirtless, wearing only shorts and shoes that appeared to be covered with both mud and/or blood, the affidavit stated. After changing into a clean pair of pants he borrowed from his co-worker, Marantos refused to let anyone handle the shorts and shoes, the fiance said. Instead, he placed them into a shopping bag he had brought with him that also contained a towel, she told police.

More evidence found in the house where Marantos had changed clothes included the victim’s broken cellphone, which had been placed into a plastic bag before being tossed in the trash, the affidavit stated.

The fiance told investigators she heard Marantos talking about some keys that came up missing at his own home and that, supposedly in the defendant’s words, an “old man” refused to help look for the keys. She told police the defendant had said he followed the “old man” outside the house and beat him up, the affidavit said.

She described Marantos as “pale white” and appearing extremely scared while talking about the man.

Marantos said on three occasions in the home of his co-worker that “I think I took it too far,” the fiance told investigators.

Another resident of the house told police he heard Marantos softly say “I think I killed him” as he was leaving in the pickup truck.

Although it had been raining, the Chevrolet Avalanche had been completely cleaned when it was returned, the truck owner told Jennings County authorities.

Later, investigators collected evidence, including human remains at numerous locations during the course of the investigation. The Indiana State Police Laboratory recently determined that DNA from the human remains matched Kirby’s DNA, investigators said.

Since Marantos has been locked up in the Jackson County Jail since April 2 on a charge of robbery, investigators are still seeking additional evidence in the ongoing case.

In Vernon, Jennings County Prosecutor Brian Belding received permission from Jennings Circuit Court Judge Jon Webster to seal the probable cause affidavit and other court documents.

But Friday, Belding said he was able to release the documents after he was sure all of the victim’s relatives knew the details of the case.

An initial hearing before Webster is likely to be scheduled after the Memorial Day weekend for sometime between May 29 and June 5, Belding said.

Find the story in Saturday’s Tribune.