Discreet 24/7 Investigations

(314) 399-8550
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Uncovering Truths, Protecting Interests

Investigations That Deliver Answers

Arch Private Investigations provides full-service investigative support for individuals, attorneys, insurance carriers, and businesses across Missouri. From surveillance and background checks to domestic cases, fraud investigations, and skip tracing, our work is built on 25 years of field experience, proper licensing, and a commitment to doing things right. Every case gets direct communication, thorough documentation, and findings you can act on. Whatever the situation, we're ready to work it.
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Key Services

Domestic Investigations

We provide discreet domestic investigations that uncover facts through surveillance, records checks, and evidence-based reporting to help clients protect their families, assets, and legal interests with confidence.

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Insurance Investigations

We provide thorough insurance investigations through fieldwork, surveillance, interviews, and documentation to help carriers, adjusters, and legal teams assess claims, identify risks, and make informed decisions.

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Surveillance

We provide discreet surveillance services that turn uncertainty into verified facts through careful planning, fieldwork, and documented evidence to support legal, insurance, and personal investigations.

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Service Areas

Missouri, Florida and Illinois (Coming Soon).

From Consultation To Case Closed

Every case starts with a free, confidential consultation where we define your objectives and outline what the investigation will involve. From there, we build a focused plan and get to work. Surveillance, research, interviews, and evidence collection are all handled personally and within full compliance with Missouri law. You get regular updates throughout, and when the work is done, we deliver a detailed, court-ready report with supporting documentation and media so you can move forward with facts, not guesses.

Michael K. Adelstein | Founder & Lead Investigator

Licensed Private Investigator | MA Criminology | BA Criminal Justice | 25+ Years Investigative Experience

Michael K. Adelstein is the founder and lead investigator of Arch Private Investigations, LLC in St. Louis, Missouri. With more than 25 years of experience across private investigations, loss prevention, and law enforcement, he leads every case personally and delivers the thorough, legally compliant results that individuals, attorneys, insurers, and businesses across Missouri rely on.

25 Years Behind The Facts

This firm didn't start yesterday. Arch Private Investigations is led by a licensed investigator with more than two decades of experience across law enforcement, loss prevention, and private investigations, backed by advanced degrees in Criminal Justice and Criminology. When you hire us, you're working directly with someone who has built a career on getting it right.
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