This one is either 70s, or early 80s, probably a made for TV movie. I initially pictured Wilford Brimley as the main character, but an IMDB search doesn’t show any movies that match what I’m looking for. Haven’t seen this movie in probably 40 years, but as memory serves, there’s an apartment building with mostly elderly living in it, that is constantly robbed and what not by local criminals and gang members. The police don’t seem to want to help, or can’t. The main parts I remember are the main character (an elderly man), finally taking matters into his own hands and constructing some self locking wrist cuffs. The next time the lead bad guy came into his apartment, he wrapped his arms around the thug, locking the cuffs behind him, therefore holding him until police arrived. Then the closing scene shows a younger kid chanting something at this old guy as he sat on a bench(?). I wanna say it was something like “The king! boomp boomp boomp boomp. The king! boomp boomp boomp boomp” or something like that.
Unfortunately, that’s all I can provide. That’s why I’m here. I can’t remember enough info to search it and find a match. Any takers?
“Siege” (TV movie, 1978)
https://www.imdb.com/title/tt0078266/
I am sure that this is the movie you are looking for. If you agree, then please select my answer as Best Answer, there is an option for that.
It is not Wilford Brimley, Martim Balsam plays the old main character. In this promo video for the movie you can see the old guy with the home made cuffs and the black guy chanting the “Boom, boom, the King…” part:
Yess! Thank you! This is the one!