Violent death and shooting in Canberra

One man is dead and another has a gunshot wound after two violent incidents in the nation's capital in the middle of the night.

A 56-year-old man was found with critical injuries at a home in Gungahlin in the city's north early on Monday, after police receive reports of an altercation.

The man died soon after, with a 30-year-old being questioned by police over the suspicious circumstances.

In a separate incident, police say bikies may have had a hand in a shooting in Canberra's south.

Three people were inside a Richardson home when a group of people are believed to have started shooting at it soon after midnight.

One person was shot in the arm and taken to hospital, with police finding five spent casings at the home.