You’ve got a DNA match with no tree attached. Just initials or a cryptic username staring back at you.
Frustrating? Sure.
But every mystery match has left clues behind.
You just need to know where to find them.
Do You Even Need to Know Who They Are?
Before you dive into Hercule Poirot detective mode, ask yourself one question.
Do you really need to know who they are?
Stick with me because this is a valid question—you don’t always need to know who every match is, depending on your goal.
If you can place them in a clear genetic cluster using shared matches, that might be enough. You know they’re connected to your Miller line from Ohio. Done.
The standard “Shared Matches” feature is the most powerful and fundamental tool for solving these mysteries.
Here’s the basic process:
- View the shared matches of your mystery person
- Create a “genetic cluster” from these connections
- Analyze the public family trees within that cluster
- Find the most recent common ancestor (MRCA)
More on clustering here.
Often, you can determine which branch of your family the mystery match belongs to without any other tools. No messaging. No searching. No building trees.
But sometimes you need more.
Maybe they’re your closest match. Maybe they hold the key to breaking through a brick wall. Maybe you’re just curious.
Here’s how to crack the case.
1. Use Ancestry Pro Tools
First port of call.
The Ancestry Pro Tools subscription unlocks an enhanced “Shared Matches” feature. Some call it “Shared Matches of Matches” (SMOM).
Game changer.
Sort by the amount of shared DNA your match shares with other matches.
Many times you’ll find a close relative—sibling, parent, child—with a nice big tree.
That tree? It’s now your mystery match’s tree too.
2. Analyze the Match’s Profile for Clues
Time to play detective.
On the Profile: Start with the username. “dbmartin79” probably has Martin in their family. Note any listed initials. Location data is gold.
Google the Username: People are creatures of habit. They reuse usernames everywhere. That same “dbmartin79” might have a forum post from 2015, or a Yelp review. Each breadcrumb leads somewhere.
I’ve had many cases where I can find their newspapers.com account where they’ve clipped articles about their ancestors.
Or maybe their FindaGrave account where they’re left ‘flowers’ for people in their tree.
Use People Search Sites: Got a potential name and location? Birth year? (remember that 79 number from the username?)
Fire up Spokeo or similar sites. These reports can provide:
Use the link above to get a $1 trial to Spokeo.
- Full names including maiden names
- Ages
- Location history
- Contact info
- Known relatives (parents, siblings, spouses, children)
- Social media profiles
- and much more
This relative list is often your breakthrough moment.
Find a Hook
People search sites can usually indicate if someone is deceased. Under the list of relatives, look for anyone who’s deceased.
That’s your hook.
Now search google, Ancestry, and newspaper archives for their obituary.
Obituaries are genealogy gold. They can list surviving family members, including your mystery match.
You can reconstruct their immediate family in minutes.
Pro tip: put the name of the deceased into the SSDI search on Ancestry. Find their death record in that database, then look at the suggested records.
3. Mine Facebook for Family Connections
Facebook is a genealogist’s dream when used right.
If they have a unique enough name or their location is listed on Ancestry, chances are you can find them on Facebook.
Check the About Section: Look for:
- Listed family members (Facebook lets people tag relatives)
- Current and past locations
- Workplace and education history
- Birthday (often visible even on locked profiles)
Search Their Posts and Photos: Even on partially private profiles, some content is visible. Use Facebook’s search function on their profile. Try terms like:
- “Mom” or “mother”
- “Dad” or “father”
- “Birthday”
Did they wish their dad a happy birthday? Perfect—now you have a name.
Did their mom comment on their profile photo calling them “my beautiful daughter”? There’s a nice clue.
Investigate Their Friends List: Can you see it? Search for people with the same surname.
Click through to these potential relatives’ profiles. Check their About sections. Do they list your mystery match as a brother, sister, cousin?
Search for Birthday Posts: This is gold. On the mystery match’s profile, search for “birthday” or “bday.” Note when people wish them happy birthday—that’s their birth date. Cross-reference with people search sites.
Check Relationship Status: Married? Maybe their spouse’s profile has more public information. Photos from weddings, anniversaries, and family gatherings can reveal entire family networks.
If the spouse has a more unique name, use them as your entry point for People Search sites. (This also goes for other family members). Find the hook.
Look at Tagged Photos: Even if their own photos are private, others may have tagged them in public posts. Wedding photos. Family reunions. Holiday gatherings. Each tag is a potential lead.
The key? People are less careful on Facebook than they think. A single comment from “Aunt Susan” can unlock an entire family line.
Creepy? Sure. But sometimes you need to break eggs to make omelettes.
4. Search for an Unlinked Tree
Common oversight alert.
Many users have family trees but haven’t linked them to their DNA results. They don’t know. They forgot. They couldn’t figure it out.
On the match’s profile page, look for “unlinked tree.” Click it. Any public trees that person owns will appear.
Even a tiny tree helps. Just parents’ names can crack the case wide open.
Pro tip: Also do a member search with their username. Some people have multiple accounts.
5. Look at the Test Administrator’s Name and Tree
Plot twist—the person managing the test might not be the person who took it.
The profile clearly states if the test is “managed by” someone else. Usually it’s:
- An adult child
- A spouse
- The family genealogist
Research the manager’s name. Look at their public trees. This strategy often leads directly to your mystery match’s identity.
The manager is more likely to respond to messages too.
6. Send a Message
But first—screenshots.
Take Screenshots First: Critical step. Capture:
- The match’s profile
- Shared DNA info
- Their shared matches list
- Any visible information
Why? Some people panic when they get DNA messages. They delete accounts. They make trees private. Your clues vanish.
Craft a Good Message: Be friendly. Be specific. Use a subject line like “Possible Smith/Jones ancestors from Ohio” not “DNA Match.”
Be Clear and Collaborative:
- Introduce yourself briefly
- Mention the DNA site and predicted relationship
- State the suspected common ancestor
- Offer to share your research
Keep it short. Make it easy to respond.
Depending on your case and your goals, contacting the match may be the last resort.
7. Message the Shared Matches
Sometimes the side door works better than the front.
Instead of messaging the mystery match, contact people in their shared match cluster. Focus on:
- Matches with public trees
- Active genealogists
- People who’ve logged in recently
These relatives might already know how your mystery match fits in. They might have the missing puzzle piece.
Active genealogists love solving puzzles. They’re far more likely to respond enthusiastically.
8. Check Other DNA Sites
Your mystery match might be chattier elsewhere.
They could have:
- A full tree on MyHeritage
- Family surnames listed on FamilyTreeDNA
- A more complete profile on 23andMe
Same username? Try it on other sites. Many testers upload to multiple databases but only maintain one tree.
GEDmatch is another option if they’ve uploaded there.
Build a “Quick and Dirty” Tree for the Match
No tree? Build one yourself.
Create a new, private, unsearchable “working” tree on Ancestry. This is your research sandbox.
Or sketch it out on Lucidchart. Or a napkin. Whatever works.
Use everything you’ve gathered:
- People search results
- Obituary
- Census records
- Public records
Obituaries and other public records can usually get you back to the 1950 census. From there, you’re golden.
Build backwards from the present. Start with what you know and work generation by generation.
Consider NPE possibilities. Non-parental events (adoptions, affairs, sperm donors) are more common than people think. Your match might not know about it.
The Reality Check
Not every mystery match gets solved. Some people value privacy. Some are adoptees still searching. Some just took the test for ethnicity estimates.
That’s okay.
Focus on the matches you can identify. Build your tree methodically. The mystery matches often solve themselves as your tree grows and more relatives test.
Remember: Always respect privacy and use information ethically when researching living people.
Some people do not wish to be contacted. Respect that.
Also read my other article: Relatives That Don’t Want to Be Related to You: The DNA Detective’s Dilemma
Your Next Move
Start with the lowest-hanging fruit. Got a mystery match with shared matches who all have trees? That’s your target.
Use the standard shared matches feature first. Free and powerful.
Save the deep detective work for the matches that matter most—your closest matches or the ones who might break through brick walls.
Every solved mystery match strengthens your genetic network. Each identification makes the next one easier.
Time to start investigating.
