DOVER-FOXCROFT, Maine — A driveway torn up by an all-terrain vehicle was the motive for a violent altercation that led to brother-on-brother murder May 1 in Dover-Foxcroft, according to an affidavit written by Maine State Police Detective Carleton Small.

Steven T. Mayo, 22, was arrested at his home at 149 French Road at about 2 p.m. Thursday and charged with intentional or knowing murder in the death of his 20-year-old brother, Ryan A. Mayo, who is survived by an infant daughter. According to documents in Piscataquis County Superior Court, Steven Mayo shot his brother in the head with a 70-year-old Russian 7.62-caliber rifle and bullets that he received in trade for a stereo amplifier about two weeks earlier.

According to Small’s affidavit, Steven Mayo and his girlfriend, Julia Raymond, returned home from grocery shopping at about 6:20 p.m. Sunday, May 1, to find the driveway torn up from an ATV doing doughnuts. Ryan Mayo had damaged his brother’s property with an ATV before, according to the affidavit, despite being told not to.

Steven Mayo told police that he walked to his brother’s home, which is located next door at 155 French Road, and began removing fuses from a four-wheeler parked on Ryan Mayo’s lawn. According to statements allegedly made by Steven to investigators, Ryan came out of his home and began pursuing Steven, eventually with a white metal pole, which Ryan used to hit his brother’s truck. Ryan also hit his brother in the mouth before stating that he was going to retrieve a gun and “blow Steven’s brains out,” according to the affidavit.

Steven retrieved the Russian rifle from his own residence. Steven told police that he brandished it just to scare Ryan, but previously had told a 911 dispatcher that he used it to shoot at the tires of his brother’s ATV. Steven admitted that fact during a later interview, according to Small. He also told the dispatcher that he had shot his brother, according to Small’s account of the recorded 911 call.

Steven Mayo told police he was carrying the rifle on one shoulder and a bag of dog food on the other when Ryan came out of his residence with a shotgun and fired it. Steven dropped the bag of dog food and shot at his brother as Ryan was re-entering his residence. According to evidence collected later at the scene, the bullet penetrated Ryan’s front door before hitting him behind the right ear. Ryan Mayo’s body was found at the base of his front steps with his left foot on the bottom step and right foot touching the lower base of the steps.

“This indicates that Ryan was attempting to enter the residence when killed,” wrote Small.

Forensic investigators were able to determine that at least two shots — one at the ATV and one at Ryan Mayo — originated from Steven Mayo’s yard. Shotgun wadding, which is plastic material expelled when a shotgun is fired, was found at the edge of Ryan Mayo’s lawn. Its location indicated that Ryan Mayo had not fired the gun in his brother’s direction, according to the affidavit.

After the shooting, Steven Mayo called his father, Kevin Mayo, and said he was “sick and tired” of Ryan doing doughnuts in his driveway and tearing up his lawn. Steven told his father that he and his brother had had a fight that ended with gunshots, and that he didn’t know if he had shot his brother. Kevin Mayo, who lived with Ryan Mayo, returned home to find Julia Raymond hysterical and Ryan’s dead body near the door to the residence.

In addition to three rifle casings and a spent shotgun shell recovered from the scene, investigators found the Russian bolt-action rifle under Steven Mayo’s couch, according to Small’s affidavit.

Maine Department of Public Safety spokesman Stephen McCausland told the Bangor Daily News that Thursday’s arrest was made after a decision by the Attorney General’s Office, which first examined evidence from the state medical examiner and crime laboratory.

Steven Mayo, who has a 2010 conviction for domestic assault on his record, is expected to make his initial court appearance in the murder case at 8:30 a.m. Monday in Piscataquis County Superior Court in Dover-Foxcroft.

Christopher Cousins

Christopher Cousins has worked as a journalist in Maine for more than 15 years and covered state government for numerous media organizations before joining the Bangor Daily News in 2009.