When Maryland police first stumbled on the bloodied and battered body of Greg Atwood, they thought he had been the victim of a tragic hit-and-run.

But when they saw a trail of blood leading to a nearby forest and discovered Atwood's own walking stick, they realized it was something far more sinister.

Ashley Elizabeth Bonilla, 15, and Mohammed Salous, 17, have been charged with murder in the 40-year-old's death. Kenneth Sahr Kpakima, 21, is also facing charges.

Montgomery County police said the three suspects robbed Atwood of his backpack, brutally beat him, and watched as he crawled into a road and was hit by two cars.

Ashley Elizabeth Bonilla, 15, and Mohammed Salous, 17, have been charged with murder in the death of 40-year-old Greg Atwood, who was found dead on a road in Maryland

Montgomery County police said the suspects robbed Atwood (pictured) of his backpack, brutally beat him, and watched as he crawled into a road and was hit by two cars

Atwood was in the Aspen Hill area around 2.45am, about a mile from his group home on the night of his death.

He was carrying a backpack of beer and using his walking stick, when he was approached by the group, police said.

Kenneth Sahr Kpakima, 21, has been charged with assault and armed robbery in relation to Atwood's death

The three suspects allegedly took Atwood's backpack. When he pleaded with them to give it back, even offering some beer in exchange, they beat him.

They used 'sticks, rocks, beer cans' as they tried to 'knock him unconscious', according to Assistant State Attorney Mark Anderson.

Investigators said Atwood then fell backward into a wooded ravine, where Kpakima and Salous followed him.

They continued to beat him until he appeared to lose consciousness for a few seconds, according to the Washington Post.

Kpakima then allegedly stole Atwood's wallet from his pocket and took out cash as the victim attempted to crawl away from them.

Atwood eventually made it onto Georgia Avenue, a six-lane road, and collapsed.

He was then hit by two cars, neither of which stopped. It remains unclear if the drivers knew they had hit someone.

The three suspects allegedly took Atwood's backpack and began beating with him as he pleaded for them to give it back

Investigators said Atwood then fell backward into a shallow, wooded ravine (pictured), where Kpakima and Salous followed him and continued to beat him

'The suspects watched the victim lay motionless in the travel lanes of Georgia Avenue,' investigators wrote in an arrest warrant.

Bonilla was charged on Wednesday with first-degree murder and armed robbery. She will be tried as an adult

'Approximately a minute later, the suspects watched a vehicle run over the victim.'

Authorities said Bonilla, Kpakima, and Salous did not call 911 and went to a nearby McDonald's instead.

Police arrived on the scene after receiving a report about a person in the road and discovered Atwood's body at 3.50am.

Bonilla was charged on Wednesday with first-degree murder and armed robbery. She will be tried as an adult.

District Judge Eric Nee denied Bonilla's attorney's request to have her transferred to a juvenile facility and said she posed a risk to other juveniles.

Atwood eventually made it onto Georgia Avenue, a six-lane road, and collapsed. He was then hit by two cars

Friends described Atwood as an 'incredibly sweet guy' who was beloved at his group home

Salous has also been charged with murder and assault-related offenses. He will be tried as an adult. Kpakima has been charged with assault and armed robbery.

Kpakima was released from jail just three weeks before Atwood's death after he pleaded guilty to attempting to steal three iPhones from a local Best Buy.

Friends described Atwood as an 'incredibly sweet guy' who was beloved at his group home.

He was an audio-video technician who struggled with depression and alcoholism but had found solace in poetry, sculpting, and painting.