Police have arrested the person they believe is responsible for a hit and run collision that killed 16-year-old Tasia Marie Gartner.

Robert Huynh, 19, was arrested on Wednesday around 6:30 p.m. at his home in McDonough after police said he tried to get his car fixed in secret.

On Monday, police said Gartner and a friend were walking along SR-81 in McDonough around 9:31 p.m. when they tried to cross the road. Gartner was hit by a car traveling west, but police said Huynh continued driving. The 16-year-old was pronounced dead at the scene at 10:30 p.m.

The severely-damaged Honda Fit used in the incident was found later at 10 a.m. Thursday at a body shop in Doraville, more than 50 miles away from the scene of the crime. Investigators initially said the car was found in Duluth. Witnesses have told police Huynh may have taken it to get repaired in Clayton County.

Huyhn is now charged with hit and run resulting in serious injury or death, failure to report accident and homicide by vehicle in the 1st degree. The GBI is processing the car for more evidence.

Meanwhile, Gartner's family said they're heartbroken over her death. Her family said she had come from a broken family and it was a cousin and her husband, Clay Ragsdale, who took her in.

Ragsdale told 11Alive that she was flourishing. "I used to call her 'My Special' because, for her life, what she's been through, it's special for her to be where she was at," he said. "Ever since the day we got her, people just congregated around her, and it's like when you're cold and there's one little bit of light, that's what she was like."

A GoFundMe page is raising money for the family. According to the page, the funeral will be on Sunday, June 25, at Memorial Park Funeral Home, 2030 Memorial Park Road, Gainesville, GA.