Police have arrested a fourth man in connection to what they say was a robbery gone wrong at a poker tournament that left one Good Samaritan dead.

Police issued a warrant for Marcus Alexis, 19, on Friday morning, but when they went to his home in Mississauga, he wasn't there. They arrested Alexis in North York later in the day, after making an appeal to the public.

Officers allege Kearn Nedd, 28, was shot during a poker tournament on April 16, 2011, when two masked men burst into the Rozz Banquet Hall and fired several shots in the course of a botched robbery attempt.

Nedd was shot after a scuffle with one of the gunmen. Police said he was acting as a Good Samaritan, as he ran to assist an organizer who was being attacked.

More than 130 people were inside the hall for the afternoon tournament at the time of the robbery and shooting.

Alexis, who is also know as "Mags," has been charged with second-degree murder.

He will appear in a Brampton court on Saturday for a bail hearing.

Three other men have already been arrested in connection with the case.

Brian Funes, 25, has been charged with accessory after the fact to murder and conspiracy to commit robbery.

Funes, known by the street name "Spanish," was in a Brampton court on Tuesday for an unrelated manner when he was charged and brought before the Ontario Court of Justice to face the charges.

In March, Peel police charged Kmar Kelly, 21, of Toronto, with second-degree murder.

A 15-year-old boy, who was 14 at the time of the incident, has also been charged with second-degree murder.