302 Cases Solved. Advancing justice for missing persons, unsolved homicides, unidentified and unclaimed remains.

Kelly Mattern Missing Person Case

Last seen in Riverside, California on Mar 6, 2023

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Victim Details

Created

May 17, 2023

Case Added

Jul 5, 2023

First Name

Kelly

Last Name

Mattern

Current Age

Age At Disappearance

Height

67 inches

Weight

145 lbs

Weight To

170 lbs

Ethnicity

White / Caucasian

Gender

Female

Last Seen

Mar 6, 2023

City

Riverside

State

California

County

Riverside County

Zip Code

92501

Tribal Land

Agency ID

125298

Agency Name

Riverside Police Department

Agency City

Riverside

Agency State

California

Agency County

Riverside County

Agency Zip Code

92505

Agency Address

10540 Magnolia Avenue, California

Agency Phone

9513542007

Agency Jurisdiction

Local

Agency Type

Law Enforcement

Agency Website

https://www.riversideca.gov/rpd/default.asp

Agency Case #

230008628

Agency Report Date

Apr 2, 2023

Primary Agency

Riverside Police Department

Case Contributors

2062

Hair Color

Brown

Left Eye Color

Blue

Right Eye Color

Blue

Last Updated

Oct 14, 2026

Area Last Seen:

Case Description

Any updates on this case? Let us know!

Summary based on the NamUs case record (MP103557) and 1 other source

Kelly Marie Mattern, a 44-year-old woman, was last seen on March 6, 2023, in Riverside, California. Her case remains unresolved, with minimal details available regarding the circumstances of her disappearance. According to public records, Kelly was known to have a history of arrests prior to going missing, but no clear connection has been established between those incidents and her disappearance.

Authorities are still seeking information on her whereabouts, and the California Department of Justice lists her case as open. If anyone has knowledge of Kelly's whereabouts, they are urged to contact local law enforcement.
Last Seen: Mar 6, 2023

Links to Additional Sources (1)

See any mistakes? Let us know!

Kelly Marie Mattern | State of California - Department of Justice

Possible Unidentified Matches (1)

Unidentified remains cases whose details are consistent with this person, ranked by how closely they compare. Fields that are unknown in either case are left out of the score.

80%Moderate

Jane Doe — Arleta, California

UP104482 • Found Apr 11, 2023

View case

Sex ✓Female

Age 100%Est. 35–50 vs 44

Race 100%White

Location 85%63 mi away, same state

TimingFound 5 weeks after last seen

Height 84%5'2"–5'5" vs 5'7"

Weight 100%125–145 lb vs 145–170 lb

Hair 100%Brown vs Brown

Eyes 0%Brown vs Blue

These comparisons are generated automatically from public NamUs case data and are not confirmed identifications. Only DNA, dental or fingerprint comparison by investigators can confirm an identity. If you believe two cases are connected, contact the agency handling the unidentified case.

Unidentified photos are blurred because many are post-mortem. Tap a photo to reveal it.

Kelly Mattern Missing Person Case

Last seen in Riverside, California on Mar 6, 2023

Victim Details

Case Description

Links to Additional Sources (1)

Possible Unidentified Matches (1)

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Forum Posts (1)

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