A “manipulative” and “charismatic” homeless man in Arizona known for “befriending others” has been arrested on suspicion of killing a 67-year-old man inside his Scottsdale townhome, according to police.
Matthew Dieringer, 35, is accused of killing Frank Quaranta, who lived near 68th Street and McDowell Road, in what police are calling a “targeted attack” discovered Monday afternoon during a welfare check after Quaranta failed to show up for work, according to the Scottsdale Police Department.
Dieringer, a Colorado native, was convicted in 2020 of beating and dismembering his roommate’s two dogs. According to court records, he received credit for 705 days served after being sentenced to 18 months in prison before relocating to Arizona.
“He has a history of homelessness and has been described as manipulative and charismatic, frequently befriending others to help him find a place to stay,” SPD officials said in a Friday press release while looking for Dieringer, who was arrested on Saturday. “If Dieringer is seen, use caution and do not approach; call 911 immediately,” the cops stated.
According to police, Quaranta was killed inside his home last Monday, September 1. It is unclear how he and Dieringer allegedly met.
“The welfare check call came into Scottsdale PD at about 1:30 p.m. on September 1, when the victim did not report to work,” according to SPD representatives. “Responding officers were unable to contact the victim in any other way and forced entry into the home to check on Quaranta.” Tragically, Quaranta was discovered dead inside. Detectives and crime scene investigators spent the next several hours searching the house for evidence.
Court records show Dieringer has had multiple run-ins with the law in Arizona and Colorado, including a recent guilty plea for theft in April and assault charges stemming from a June 2024 incident. He has previously been arrested for criminal mischief and burglary.
According to local ABC affiliate KRDO, Dieringer killed and dismembered two dogs belonging to a roommate in Teller County, Colorado, in 2020. Cops entered their home and discovered the walls covered in blood and evidence of a struggle, including multiple holes and a blood spatter spot that appeared to show Dieringer slamming the animals.
“The scene we went into was difficult,” Trixie Hudspeth, Teller County Sheriff’s Office Animal Control Officer, told the outlet.
According to KRDO, neighbors reported hearing yelling and seeing Dieringer in a “enraged mental state” the night before police arrived at the home. The dogs’ remains were discovered in a plastic tote and a bathtub drain, along with tooth fragments and dog hair.
Dieringer eventually pleaded guilty to felony aggravated animal cruelty. He was held without bond over the weekend in connection with Quaranta’s death. Cops have not said what charges he is facing.
