He says these were professional thieves who knew what they were after.

The first, which turned up you, was for a professional thief without a record of violence.

Before, no professional thief would kill; it was a kind of code.

Perhaps he was a professional thief and finally went to prison for it.

This makes it difficult for professional thieves to tow your car away.

By the time an alarm sounds, most professional thieves are gone.

These days, he said, art books are taken by professional thieves.

Besides, for most professional thieves, door locks were the least of their problems.

They're about a man named Parker who is a professional thief.

What were the differences between the ordinary and professional thieves?