Kevin Gregson, 45, remained silent as he was also found guilty of robbery.
A jury of eight men and four women delivered the verdict Tuesday night following nine hours of deliberations.
The Crown had argued Gregson meant to kill Czapnik, 51, as they struggled early on the morning of Dec. 29, 2009 outside the emergency room at the Civic Hospital.
But Gregson, a former Saskatchewan RCMP officer, said he just wanted to grab the officer's gun so he could return home and kill himself.
During his testimony, Gregson told the court of his troubled personal and professional life. He had been dismissed from the RCMP for disciplinary and behavioural problems.
In her victim impact statement, Czapnik's widow, Anna Korutowska said, “there is one statement that I agree on with my husband’s killer. Eric was a good man.”
Korutowska later told reporters, “I believe justice has been served.”
Matt Skof, president of the Ottawa Police Association, released a statement late Tuesday night, saying members of the association were pleased with the verdict.
"The murder of Eric Czapnik by Kevin Gregson was heart breaking for Eric's family and his extended police family as well," Skof said in the statement.
"While this conviction does not bring Eric back, it is another step in the healing process for all of us. Eric will live on in our hearts and minds; we will never forget him," Skof said.
First-degree murder carries an automatic penalty of life in prison with no chance of parole for 25 years.
Gregson had been suspended with pay in September 2006 after allegedly threatening a Mormon bishop in Regina. His pay was revoked after he pleaded guilty in April 2007.
The RCMP then launched an internal disciplinary process, overseen by an adjudication board. In July 2008, the board ordered him to resign or be dismissed. He appealed the ruling and remained on unpaid suspension.
Czapnik, who was married with four children, joined the police force in his late 40s. The Polish immigrant moved to Canada in 1990 and eventually followed in the footsteps of his father, who was an officer in Poland for 30 years. (CFRA)