The grammar is mostly good, and the few trivial errors do not detract from the message.
The worst grammatical mistake is "During their patrolling, police officers could stop and document..." with its completely gratuitous use of "could." The sentence should say "During their patrolling, police officers stop and document... "
The real problem with the passage is the long complicated sentences (especially the first one.)
In addition, some of the elements should be re-arranged (For example, the sentence that begins "Carding policy is... " should be attached to the first sentence, not floating around separated from it.)
The passage is a high C or low B in a freshman college English course.
Here is a way to re-structure it that you may be able to use:
Carding policy, a practice that is also referred to as "street checks," is one example among many of lingering stereotyping, prejudice, and discrimination in Canada. During their patrolling, police officers stop and document individuals in what are usually non-criminal encounters. According to the Toronto Star's recent analysis of Toronto Police Service (TPS) carding data from 2008 to 2012, African-Canadians remained three times more likely than white people to be carded.
It's always worth while to decide which idea is the main one. Then structure the paragraph to end on that idea.
Many times, student writing just trickles out with boring details piled on at the end, like this:
> Suddenly he saw a gigantic snake coiled in the corner of the bedroom, in the part of the room near the bed which was seldom illuminated by the sun even at noon on the brightest days.
Really, by the time you've read all these reflections on room decor, you have kind of forgotten about the gigantic snake.
But it is an easy matter to rearrange the sentence elements to put the snake at the end, like this:
> Beside the bed, in the part of the room that the sun never reached, lay coiled a giant snake.