I've had actual experience with the frustration of getting permission to cross the Canadian border. In 2011, my partner started the process of contacting the Embassy in NY in preparation for our planned trip to Alaska the following year. No phone calls are accepted. She had been arrested when she was 21 and hanging out with the wrong people. One time only, minor offense reduced to misdemeanor, 40 years ago. The hoops she had to jump through included getting police reports from two states, FBI search report, fingerprints in two different methods for each state, local township police report showing she hadn't been in any trouble, $200 money order to be sent to Canadian Embassy with all forms, documents, fingerprints, reports, and copies of court findings. The fingerprints and police searches cost about another $200.
We kept waiting and waiting to get an answer before leaving for Alaska the next year. Nothing. No answer to emails or letters. We left anyway and had no trouble crossing the border either time. Lucky.
Two and a half years after we mailed the package to Canadian Embassy, she got a letter granting her permission to enter Canada from now on.
YMMV.
