LONDON, Ont. -- Tristan Roby is home, and although he's already come quite far, it's clear he still has a long way to go.

Tristan was hit by a car along Exeter Road on July 23, 2019. Police say the suspect stopped, but then fled the scene. The 18-year-old was critically injured.

Now, he breathes on his own. But with a traumatic injury, his mother, Abby Roby, says doctors and the family are at odds over how much more he’ll recover.

“If I'm answering that question as a doctor...this would be it. If I am answering that question for myself, and for Tristan, I think in a year, he'll be walking and talking."

To prove her point, Abby demonstrated for CTV News something she says Tristan has just started doing, communicating with his hands.

"He either answers with squeezing, or he answers like this, once for ‘yes’, and two for ‘no’."

Although not definitive, Tristan appears to move his thumb when asked questions by his mother and CTV News.

One of the questions was “Are you happy to be home?” His thumb appeared to move indicating ‘yes’.

But while the environment may be more familiar, bringing Tristan home comes with an emotional and financial cost.

On Tuesday, a series of caregiver agencies arrived to offer support to the Roby family.

Their primary focus will continue to be Tristan’s ongoing care, but they also keep a close eye on the police investigation.

To date, an arrest has not been made, but Abby remains hopeful the person responsible will step forward, or be apprehended by police soon.

“(Tristan's) got to fight for every action, every subtle movement he makes. Whereas the other person gets to runaround and do whatever they want."