Andy Summers’s review published on Letterboxd:
The first couple of Dirty Harry films were a class apart from the other three films that followed over the course of the next 15 years. The Enforcer had elements of that subversive undercurrent that had been prevalent in Dirty Harry and Magnum Force, but both Sudden Impact, and The Dead Pool especially, had lost that edge and air of menace that Callahan's character had in abundance. He may still have been dirty Harry, but something was missing from the later films, maybe we just weren't as shocked as we had been back in the early seventies.
Sudden Impact features a rape/revenge storyline that has Eastwood's real life squeeze Sondra Locke as the main protagonist. Having been the victim of a gang-rape that also left her sister traumatised, Locke's Jennifer Spencer has waited 10 years to finally exact revenge on the perpetrators. One shot to the head and another to the bollocks becomes her modus operandi, and that's where Clint's Callahan becomes involved as the bodies start to stack up. There's a bit of a conspiracy involving the local sheriff, a few well chosen ugly bastards as the rapists, and a token bitch as the one who betrayed the sisters. Callahan meanwhile is also a target for the mob after he caused a crime-boss to have a fatal heart-attack, so Harry's dodging bullets from the off. There's still time to give a few henchman some toe-tags, start a romantic liaison with Locke's killer, which comes across as strange even for a Dirty Harry film, and piss off the local sheriff played by Eastwood's own close friend Pat Hingle. It's a mixed bag indeed, and probably the second worst film in the series behind The Dead Pool which was dire despite a great premise.
This is the only Dirty Harry film directed by Eastwood himself, and for a guy who could normally be banked upon to deliver as a director, this isn't up to his usual standard. However, here's an interesting little fact from the franchise. Albert Popwell featured in the first four films in the series as four different characters. A bank-robber shot by Harry in the first film, a pimp murdered by David Soul in Magnum Force, a black militant in The Enforcer, and Harry's detective buddy in Sudden Impact. So he's killed in two films, banged up in another, and left alive in The Enforcer as the wonderfully named Big Ed Mustapha. Twelve years, four films, old Albert almost made a career out of being typecast?