LOVE CAN LEAD to terrible acts when it grows possessive.June Thomson, who writes of crimes with chilling psychological overtones, explores The Habit of Loving (Doubleday -- Crime Club, $7.95) in her sixth novel featuring Inspector Rudd, another compassionate policeman who deals with people as well as clues. It is a strange triangle: a lonely middleaged maiden lady; her boarder-surrogate son with a mysterious past; a young unwed mother who arranges a clandestine date under the watchful eye of her father. And it has an unusual, even poignant, solution in Thomson's skillful hands.

Antonia Fraser apparently tosses off mysteries in spare moments.At least, the book jacket informs us that The Wild Island (Norton, $8.95) was written while Fraser has been working on a biography of Charles II to follow her Mary Queen of Scots and Cromwell.

The problem is that one just doesn't toss off a mystery, at least a good mystery novel. Quiet as a Nun, Fraser's first, had promise, particularly in the scenes drawn from the author's memories of a convent school education. If the solution seemed strained, the heroine, Jemima Shore, a television investigative reporter, was not without a certain charm. In The Wild Island, Jemima, well supplied with the poems of Burns and the novels of Scott, seeks a vacation retreat on a remote Scottish isle and becomes involved with the Red Rose, a small band of Scottish freedom-fighters. They are more preposterous than menacing, and poor Jemima, liberated, it turns out, only in her sexual mores, loses her spirit and becomes a conventional damsel-in-distress. It's over-atmosphered, overwritten, and under-plotted.

In Michael Kirk's Salvage Job (Doubledy-Crime Club, $7.95), Andrew Laird, the resourceful marine insurance investigator, finds himself in deep water when he is sent to a Portuguese fishing village to handle the claim on a 50,000-ton oil tanker stranded on the rocks after a storm. A drunken crew member swears that he saw a huge whale; the diver hired by Laird dies when his oxygen tanks are filled with carbon monoxide, and Laird himself gets entangled in an international diplomatic trade-off. The characters are salty individuals, and Kirk (also known as Bill Knox and Noah Webster) writes knowledgeably of both the commerce and romance of the sea.

Peter Alding offers another welldone British police procedural with Murder Is Suspected (Walker, $7.95). Detective Inspector Fusil persists in the investigation into what seems just another hit-and-run after the chief constable, whose son is suspected, resigns and invites inquiry. Alding handles the plot deftly and gives substance to the characters of the persistent Fusil and the troubled chief constable, a former army officer bedeviled by integrity and an unhappy marriage.