Scottsdale police are on high alert after a 67-year-old man was found dead inside his home in what authorities are calling a “targeted killing.” The suspect, 35-year-old Matthew Dieringer, has a long and troubling history of criminal behavior, and now law enforcement is urging the public to stay vigilant.
Welfare Check Leads to Grim Discovery
Officers were called to Frank Quaranta’s home early Monday morning around 1:30 a.m. for a welfare check after he failed to show up for work.
When they couldn’t reach him by phone, they forced entry into the residence. Tragically, Quaranta was found dead inside.
Police and crime scene specialists spent hours combing the property for evidence.
The exact circumstances of his death are still unclear, and authorities have not confirmed a motive or any connection between Quaranta and Dieringer.
Suspect’s Troubling Background
Matthew Dieringer is no stranger to law enforcement.
Authorities describe him as “manipulative and charismatic,” noting that he often befriends people to secure housing. He has a history of homelessness and a criminal record spanning multiple states, including arrests for assault, burglary, and criminal mischief.
Dieringer previously lived in Colorado, where he faced serious allegations, including the shocking killing of his roommate’s dogs in 2020.
Investigators discovered blood-splattered walls, holes in the mobile home, and a severed dog tail submerged in water.
The disturbing scene also included other dog remains and fragments found in the bathtub drain.
Neighbors recalled witnessing Dieringer in an enraged state the night before deputies arrived, with yelling and aggressive behavior reported.
Protective Orders and Prior Incidents
Court records indicate that at least one family member sought a protective order against Dieringer, highlighting a pattern of concerning behavior.
His past actions, combined with his ability to charm and manipulate others, have made him a person of interest for law enforcement in multiple states.
Police Urge Caution and Public Awareness
Arizona authorities are warning the public not to approach Dieringer if spotted.
He is described as standing six-foot-three, with blonde hair and blue eyes.
Anyone with information about his whereabouts is urged to call 911 immediately.
Law enforcement continues to investigate the connection between Dieringer and Quaranta, and the search for the suspect remains ongoing.