Thomas McPherson, a Millvale resident and unsuccessful Republican mayoral candidate in the borough last year, was arrested yesterday on charges that he threatened a minority family moving into a residence next door to his house. Mr. McPherson, 46, of Sample Street, was charged with ethnic intimidation, simple assault, terroristic threats and disorderly conduct. Police said after words were exchanged between Mr. McPherson and members of the family, Mr. McPherson went inside his house and came back out with a gun in its holster strapped on his body. Police said he pulled the gun half-way out at one point in the...