A DNA expert has offered “likelihood ratio” testimony in the trial of two co-defendants who are on trial for leading police officers on a high-speed chase through downtown Cheyenne while shooting guns.

The Chase

On May 3, 2019, Chasity Jacobs and Dominique Childers were arrested following a high-speed chase and shootout that took place in downtown Cheyenne, Wyoming.

Authorities claimed that Childers was driving a stolen 2016 Toyota Camry along Interstate 25 at speeds of up to 115 miles per hour while attempting to avoid being pulled over. Police reports also claim that Childers was driving through downtown Cheyenne at speeds close to 65 miles per hour.

During the chase, multiple shots were fired at a Wyoming Highway Patrol Cruiser and a Cheyenne Police Department cruiser. Both vehicles were struck several times.

The chase ended only after Childers was shot by Cheyenne Police Department officers who were in pursuit of the vehicle.

Jacobs was initially charged with a felony charge of taking a controlled substance into a penal institution (later dropped) and misdemeanor possession of methamphetamine.

Childers allegedly told the police that Jacobs hadn’t fired a gun and he was responsible. However, as Wyoming Division of Criminal Investigation investigated the case, agents claimed to have found Jacobs’ DNA on a 9mm Ruger pistol, two magazines, and the magazine from the other gun used in the shooting. Two recorded phone calls made by Jacobs from Laramie County Detention Center also allegedly implicated her in the shooting.

Jacobs was charged with attempted first-degree murder, first-degree accessory to murder, reckless endangering with a firearm and misdemeanor possession of methamphetamine.

Childers was charged with two counts of attempted first-degree murder, two counts of felony property destruction, felony possession of methamphetamine, two counts of misdemeanor property destruction, reckless endangering conduct and eluding.

DNA Expert Witness Testimony

The state called Jennifer Brammeier as a DNA expert witness. Brammeier is employed by the Wyoming State Crime Lab. The state asked Brameier to testify about DNA evidence collected from the weapons and ammunition used in the alleged shooting.

Brammeier explained that she used a “likelihood ratio” when testing the DNA evidence. This means that she matched the DNA collected on the evidence to reference samples to see if there was a correlation with the DNA. Childers and Jacobs had given reference samples of their DNA for the DNA evidence analysis.

Brammeier compared Childers’ and Jacobs’ DNA profiles to DNA that was found on evidence such as the guns and ammunition found inside the black sedan that was used during the chase. She was able to identify DNA that correlated to that of Childers and Jacobs on both the guns and ammunition.

Cassie Craven, defense attorney for Jacobs, questioned Brammeier about how DNA transfers between objects. She asked whether a person’s DNA could be transferred to an object that he or she never touched. Craven used the following example: If she was touching the courtroom podium and someone else touched that podium and then the door knob, would it be possible for her DNA to be transferred to the door knob, even if she had never touched it herself?  Brammeier replied that this type of DNA transfer is possible.

Brammeier also clarified that it is not possible to determine when or how the DNA was transferred to the objects where it was found.