DNA expert testifies at La Mesa murder trial
Preston Strong’s DNA was found on the steering wheel of a Dodge Durango belonging to Luis Rios that was found abandoned in the area of 21st Street and 6th Avenue the morning after six people were murdered, according to a scientist who testified Tuesday.
Lorraine Heath, a former forensic scientist from the Arizona Department of Public Safety’s Crime Lab, testified in the capital murder trial of Strong, who is charged with six counts of first-degree murder, one count of armed robbery and one count of burglary in the 2005 case.
Heath, who now works as a supervisor for the Washington State Patrol Crime Lab, told jurors that swabs taken from the vehicle’s steering wheel revealed DNA from at least four people, and that Strong was found to be the significant contributor of one of DNA profiles that was found.
Under direct-examination by prosecutor John Tate of the Yuma County Attorney’s Office, Heath testified that Rios was the other significant contributor of DNA, which was expected since he was the owner of the vehicle, but they did not know who the other contributors of DNA were.
She explained that alleles are in a specific location in a DNA strand, and that she was able to create a partial profile of one of the other significant contributors of DNA from the steering wheel by using those positions.
After receiving a DNA sample of Strong in March of 2006, Heath said she then compared it to that partial profile, and several of the key allele positions matched a strand of his DNA exactly.
She also testified that to have been a significant contributor on an item such as a steering wheel, which is touched often, a person would have to have been in contact with it shortly before a DNA sample was taken.
But Strong’s attorney, Raymond Hanna of Prescott, tried to cast doubt on the validity of the results by questioning the statistical method used, other ways DNA could have gotten on the steering wheel, and who the other two contributors of DNA were.
Under cross-examination by Hanna, Heath testified that the partial profile was also tested against 16 other profiles, 10 of which were excluded as the source, while six others were determined to be inconclusive.
She also testified that she tested 35 items of evidence in the case, including bindings, and was not able to collect any DNA from any of the items.
However, when under redirect by Tate, Heath explained that DNA from a suspect is not typically found on bindings because a majority of the DNA comes from the person being bound.
Strong, who is also being represented by William Fox of the Yuma County Public Defender’s Office, is currently serving two life-term sentences with no chance for parole for the 2007 murder of Yuma physician Satinder Gill.
On June 24, 2005, six people were killed at 2037 E. La Mesa St.: Luis Rios, Adrienne Heredia, 29, and her four children — 13-year-old Andreas Crawford, 12-year-old Enrique Bedoya, 9-year-old Inez Newman and 6-year-old Danny Heredia.