News Summary
Matthew Dieringer, a 35-year-old man, has been arrested for the alleged murder of his 67-year-old roommate, Frank Quaranta. Quaranta was found dead during a welfare check after concerns about his absence from work. The Scottsdale Police Department labeled the incident a targeted attack, emphasizing Dieringer’s manipulative nature. Dieringer has a criminal background, including a previous conviction for a violent crime. He is currently being held at the Maricopa County Jail, facing significant charges and potential life sentences.
Scottsdale, Arizona – A 35-year-old man, Matthew Dieringer, has been arrested for allegedly murdering his 67-year-old roommate, Frank Quaranta, during an attack on Labor Day. Quaranta was discovered dead in his home during a welfare check on September 1, 2025, following concerns over his absence from work.
Quaranta was found at his residence near 68th Street and McDowell Road after police were notified by colleagues who had not seen him for several days. When officers entered the home, they found his body displaying signs of blunt force trauma, indicating a violent altercation had taken place. Dieringer was quickly identified as the primary suspect in the case.
The Scottsdale Police Department characterized the incident as a “targeted attack” and warned the public that Dieringer is considered both manipulative and charismatic. He reportedly befriended individuals to secure places to stay, which included his living arrangement with Quaranta. Dieringer had been living with Quaranta for several months after they met at a church outreach program designed for the homeless.
Prior to his arrest, authorities had received tips from community members warning that Dieringer should not be approached due to his violent tendencies. He was eventually apprehended near 13th Street and Indian School Road in Phoenix when a citizen recognized him from a recent news report. Initial apprehension led to a violation of probation stemming from a theft case in 2024.
Dieringer’s criminal background includes a previous conviction in Colorado in 2020 for the death of his roommate’s dogs. The severity of his current charges has raised significant concerns regarding public safety. Following his capture, authorities noted that evidence collected from the murder scene, including a presumptive DNA match linked to Dieringer, has solidified the case against him.
During his initial court appearance, Dieringer maintained that the allegations against him were incorrect and claimed the proceedings were illegal. However, prosecutors painted a stark picture of the events leading to Quaranta’s death, deeming the act “violent and horrific.” They allege that Dieringer beat Quaranta to death, which has resulted in the state seeking a cash-only bond of $3 million due to fears for community safety alongside Dieringer’s extensive criminal history.
As proceedings continue, Dieringer is being held at the Maricopa County Jail, with additional charges expected to follow. He has a court date scheduled for his murder charge on September 12 and another for the probation violation on September 15. If convicted of murder, he faces the possibility of a life sentence or even the death penalty.
This incident has shocked the local community, highlighting issues surrounding the safety of individuals who might be vulnerable or living in transient situations. Authorities remain vigilant, emphasizing the importance of public awareness in addressing such serious criminal activities.
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Additional Resources
- Fox 10 Phoenix
- Wikipedia: Murder in the United States
- AZ Family
- Google Search: Scottsdale murder suspect Matthew Dieringer
- KTAR News
- Google Scholar: Violent Crime and Community Safety
- Denver 7 News
- Encyclopedia Britannica: Criminal Justice
- ABC 15 News
- Google News: Arizona Murder Case
Author: STAFF HERE PHOENIX WRITER
PHOENIX STAFF WRITER The PHOENIX STAFF WRITER represents the experienced team at HEREPhoenix.com, your go-to source for actionable local news and information in Phoenix, Maricopa County, and beyond. Specializing in "news you can use," we cover essential topics like product reviews for personal and business needs, local business directories, politics, real estate trends, neighborhood insights, and state news affecting the area—with deep expertise drawn from years of dedicated reporting and strong community input, including local press releases and business updates. We deliver top reporting on high-value events such as the Waste Management Phoenix Open, Cactus League Spring Training, and Arizona State Fair. Our coverage extends to key organizations like the Greater Phoenix Chamber of Commerce and Visit Phoenix, plus leading businesses in technology and healthcare that power the local economy such as Intel and Banner Health. As part of the broader HERE network, including HERETucson.com, we provide comprehensive, credible insights into Arizona's dynamic landscape.
