PITTSBURGH — A state lawmaker was charged with simple assault on a former girlfriend following an argument at his office, police said.

The woman confronted Rep. Joseph Preston, 60, in his district office on Sunday night, unhappy that he wanted to end their relationship of about a year police said.

Police were summoned after Preston escorted her from the office and she found she had a minor injury to her arm, which police described as "redness and scratching." The woman told police Preston grabbed her arm and throat and forced her out the office, according to a criminal complaint.