Summary

On November 14, 2011, 20-year-old Andrea Eilber was found bound to a chair and shot in the head at her aunt and uncle’s home in Mayfield Township, Michigan. Eilber had been house-sitting while her relatives were out of town. When she failed to respond to calls and messages, concerned family and friends launched a search. Her car was discovered abandoned on a nearby road, and when authorities entered the home, they found her murdered.

Initial investigations led police to her then-boyfriend, Kenneth “KC” Grondin, who was arrested and charged with the crime. Although Grondin was convicted following a 12-day jury trial in 201, his conviction was overturned in 2018. Grondin was set for a retrial, but proceedings were delayed as new evidence emerged.

One piece of evidence in the case was a cigarette butt found at the crime scene. In 2011, forensic testing identified a single male DNA profile that did not match anyone known to be connected to the case. Over the years, investigators compared the DNA profile to many individuals, but they found no matches.

In 2022, the Michigan State Police submitted the forensic evidence to Othram's laboratory in The Woodlands, Texas. Othram scientists used Forensic-Grade Genome Sequencing® to develop a comprehensive DNA profile from the cigarette butt. Othram’s in-house forensic genetic genealogy team used the profile in a forensic search and developed new investigative leads which were returned to law enforcement.

A follow-up law enforcement investigation led to Chadwick Shane Mobley as a potential contributor of the DNA from the cigarette butt. At the time of the murder, Mobley worked as an EMS technician in Pontiac, Michigan and lived in nearby Auburn Hills. Mobley's name never surfaced during prior investigations, making forensic genetic genealogy an important tool in helping to identify him as suspect in the case.

Once Mobley was identified, law enforcement in Utah and Montana worked with the Michigan State Police to conduct surveillance on him. Mobley, a long-haul truck driver, was living out of his truck and rarely disposed of items that could provide discarded DNA. Despite these challenges, authorities eventually obtained a confirmatory DNA sample, which matched the crime scene evidence. In June 2023, Mobley was arrested in Montana and later extradited to Michigan to face murder charges.

On February 17, 2025, the Michigan Attorney General’s Office announced that Mobley pleaded no contest to first-degree premeditated murder, felony murder, and felony firearm in Lapeer County’s 40th Circuit Court. His sentencing is scheduled for April 15, 2025, where he faces a maximum sentence of life imprisonment without the possibility of parole.

The identification of Chadwick Shane Mobley is the 16th case in Michigan where officials have publicly identified an individual using technology developed by Othram. Visit DNASolves to learn about other Michigan cases.