Examples of communiques by serial killers, according to a study by Tomas Guillen, who teaches journalism at Seattle University:

LIPSTICK KILLER: "For heaven's sake, catch me before I kill more; I cannot control myself," said the message scrawled in lipstick on a wall in the home of one of the Chicago killer's victims in 1946. Another victim's family was sent a letter demanding $20,000 in ransom.

William Heirnes was arrested for the murder of a girl and two women after being caught breaking into an apartment; his fingerprints matched those on the ransom note.

ZODIAC KILLER: "I get awfully lonely when I am ignored, So lonely I could do my Thing," the Zodiac Killer of San Francisco said in one of many letters, cards, phone calls and ciphers in the 1960s and 1970s. The killer of at least six people and possibly many more was never caught.

The messages mainly taunted police and conveyed details only the killer could have known but were of little investigative value.

WICHITA KILLER: "How about some name for me, its time: 7 down and many more to go." So said the killer of four members of a Wichita, Kan., family and at least three other people in the 1970s. His first letter was found in a textbook at the public library; he went on to send poems and called police with details of one slaying. He wanted to be called BTK, for bind, torture and kill.

The communiques sent police down wrong paths and the case remains unsolved.

WEEPY-VOICED KILLER: "I'm sorry for what I did," the killer whimpered into the phone during his series of murders and beatings in Minneapolis in the early 1980s. Three women died and two were wounded in the attacks. The distraught killer repeatedly called police and authorities released the recordings in the hope someone would recognize his voice. But his calls were too short and his voice was too distorted by emotion.