McCrary

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• Suspect 'has passion' about abortions
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FREDERICKSBURG, Virginia (CNN) -- A retired FBI criminal profiler believes last week's killing of an abortion provider near Buffalo, New York, was planned long in advance and that surveillance of other targets may be in the works.

Gregg McCrary put together a profile of the killer based on information he received from various law enforcement sources following the death of Dr. Barnett Slepian, a frequent target of anti-abortion demonstrators.

Slepian, 52, was shot dead on Friday by a bullet fired into his home in the Buffalo suburb of Amherst. No arrests have been made but the bullet that was used in the shooting was recovered intact on Tuesday.

Describing the killer as cowardly, McCrary says the person probably spent a great deal of time "casing the joint," to carry out the attack.

Such a criminal will "go to great lengths to avoid apprehension," says the retired FBI profiler, who continues to work with the National Center for Analysis of Violent Crime at the FBI Academy in Quantico, Virginia.

The shooter has most likely begun surveillance of other potential targets, McCrary told CNN in an interview from his home in Fredericksburg, Virginia.

As a result, he said, those who might be at risk should pay more attention to unknown individuals seen observing the comings-and-goings at clinics and medical offices or the neighborhoods where potential targets live.

Authorities investigating the Slepian killing will have to look back many months to uncover whether the victim's neighbors recall seeing anyone unusual, McCrary said.

McCrary's profile says the suspect is "probably employed, may have family, may have sort of a typical lifestyle, but those around him will know that he has this passion about the abortion movement."

Anti-abortion groups could prove helpful as authorities try to find the killer, McCrary told CNN. "This is a person who probably has been involved in the mainstream anti-abortion movement. Those people can be helpful by thinking of those who have come and gone, and perhaps were too radical or too outspoken."

The killer may have voluntarily left an established anti-abortion group because it was "too tame," he said.

McCrary believes it's possible the shooter had help from a "support person or subordinate of some sort."

The ex-FBI man also sees the possibility copycat attacks. "There may be other people who are on the edge who identify with this offender and that moves them that much closer to acting out themselves," he said.