There are some excellent comments and observations on this film. I was pleased to note the comparisons to Fritz Lang's "M" (forget the 50's abortive remake with lightweight David Wayne). The real villain is not the tortured murderer (extraordinarily fine performance by Jeffery DeMunn), taking out his sexually frustrated anger on his victims-- mostly children. He is the objective. The real villain is the stifling bureaucratic Soviet system, drowning in its own corrupted incompetence. The frustration of an uncompromisingly dedicated man (Rea in his best role since "The Crying Game"), a facile pragmatist who's willing to use the system to his advantage (Sutherland always successful in this kind of role), a hesitant, frightened but determined psychiatrist (the incomparable Max Sydow), the bumbling, boopous bureaucrat of a prosecutor (brilliant Brit actor John Wood) and the quiet, supporting wife of the driven investigator (delightful supporter, Imelda Staunton). This is one damn fine film. Its darkness and bleakness are supported by the portrayal of a corrupt, incompetent system which works against success. The is no need to dip into gore-laden slice 'n dice sensationalism that has characterized so many recent films. Gore is present-- it's a ghastly story-- but it adds to the depicting of a pathologically twisted human being. The success of the story is precisely that: these were acts perpetrated by a person, a human like you or I. Where you and I choose to vent our frustration by reasonable means, Chikatilo took his anger out on the most innocent and vulnerable of us, our children. The superb premise of this story is made manifest by an equally superb cast of excellent actors. --sadly, I note that our Australian friend didn't like the speech and no doubt would have preferred to hear them speaking in Aussie dialect. Well, too bad. This fine film sure worked for me and everyone else I've talked with who has seen it.

The original 1965 Japanese film "Gamera" http://pro.imdb.com/title/tt0059080/ was essentially an updating of the darker, less kid-oriented Gojira (Godzilla)for 1960s sensibilities. Gamera, of course, is a giant, flying, flame-throwing turtle who literally consumes energy - not quite as big as some versions of Godzilla, but generally similar in most ways.
This version of the original film was edited and recut by the notorious Sandy Frank. And just like the Americanized version of Godzilla ("Godzilla King of the Monsters"), "Gammera the Invincible" gets more than just the spelling wrong. The American scenes are not nearly as ludicrous and annoying as those added to the great Gojira, but don't really add much to the story either because there is little follow up on them.
The film starts off promising, there are a few scenes worth of character development, and there are enough personalities to create some tension outside of the main plot. Once Gamera appears, however, the film begins to descend into a fairly run-of-the mill kaiju film.
The acting is good enough- even the American add-ons are OK. The directing is pretty good for this period and genre, and the special effects are not bad at all for their time (all miniatures). Some of the sets and backdrops are actually very good.
The biggest problem here, of course, is that there is little to nothing original about this film. Gamera, however, develops a much more unique personality in his later films - most of which are worth watching if you are a kaiju fan.