Hamilton police say they have located a key witness in the shooting death of a 19-year-old Good Samaritan who authorities say was killed while trying to stop an altercation.

Yosif Al-Hasnawi, described by police as a brave young man who was trying to do the right thing, was fatally shot in early December after he tried to help an older man who was allegedly being accosted by two men outside a mosque.

Police say the older man was interviewed Wednesday afternoon after someone called in a tip that led investigators to find him.

Officials say the tip came in after police released photos of the man earlier in the week in the hopes that someone would recognize him.

They say details of the interview cannot be released.

Two men have been charged in connection with Al-Hasnawi’s death, and a criminal investigation into paramedics’ handling of the incident was launched last month and is being carried out by a neighbouring police force.

Al-Hasnawi’s family is also suing Hamilton’s paramedics, alleging they failed to properly treat the teen.

Read more:

Family of slain Good Samaritan suing Hamilton police, paramedics and hospital

Hamilton police say criminal probe launched into emergency medical response in Good Samaritan’s death

Police seek older man rescued in Hamilton Good Samaritan shooting