Forensic analysis was not able to establish a DNA link between several already-euthanized dogs and the homeless woman they were suspected of mauling to death, Dallas police have announced.

Antoinette Brown, a 52-year-old homeless veteran, was attacked by four to five loose dogs in May, resulting in more than 100 bites that exposed bone and ultimately caused Brown’s death a week later. No eyewitnesses could identify the dogs, but residents in the area who reported hearing Brown screaming for help, directed Dallas police to a nearby home known to have loose dog complaints.

Four days later, Dallas Animal Services took possession of seven dogs from that house, with the owner’s permission. At this time, the police collected other evidence and DNA samples for testing. According to the Dallas News, the dogs were then humanely euthanized.  

Samples were sent to the Southwest Institute of Forensics Science and the University of California at Davis’ Veterinary Forensic Lab for DNA processing. Results from both labs came back negative for a match between the dogs that mauled Brown and the dogs that were seized and euthanized.

Subsequently, the Dallas Police have closed the case. Prior to the announcement on Monday, they were pursuing the case as an “attack by dog,” which would have held the dogs’ owner criminally responsible. Since the attack caused a death, the owner could have been charged with a second-degree felony.

Animals, forensics and DNA

Although not the case in the death of Brown, for the most part, extensive advancements in DNA testing have benefited animals, especially wildlife.

Just a few years ago, for example, a bear attack in a National Park would have forced rangers to kill any suspect bear in the general premise of the attack. Now, however, rapid DNA tests can identify precisely which bear did the attacking, sparing the lives of the innocent.

Such was—mostly—the case in May, just a few days after the Dallas dog attack in the Great Smokey Mountains National Park in North Carolina. An experienced hiker pitched a tent for the night, only to be beaten in the leg by a black bear through the tent. After leaving the hiker with one-and-a-half inch deep holes in his calf, the bear attempted to enter the tent through an opening.

The hiker was able to escape to cabin shelter by yelling and hitting the bear long enough to pose a distraction. The next morning, his tent was shredded and gear was full of teeth marks.

Within a few weeks, park rangers had found three male bears lurking in the attack area, including a 400-pound bear that was mulling around the attack campsite.

DNA was taken from all three bears and sent to Western Carolina University’s (WCU) Forensic Science Program to test against the sample from the hiker’s ravaged gear.

Scientists at WCU used an optimized DNA testing protocol they developed that can be delivered and completed in a day or two—compared with previous methods that required shipping the samples to other labs and waiting, a process that could take in excess of weeks.

“We’re taking DNA techniques from human criminal investigations and using them on black bears,” WCU geneticist and co-developer of the rapid response DNA testing, Maureen Hickman, told BuzzFeed News. “It worked beautifully, there was a lot of saliva on the tent shreds, and there were bite marks on a phone and a book.”

Ironically, the extremely short turnaround time wasn’t short enough to save the 400-pound bear. He was too big for a tracking collar and too big to go to the zoo, and park rangers were hesitant to release that large of a bear that may have—and at this point they thought did—kill a hiker. So, park biologists shot and killed him.

On the other hand, the two smaller bears were held during DNA testing—which subsequently cleared all three bears of the attack. The two smaller bears were fitted with tracking collars and re-released to the national park ASAP.