WALTHAM (AP) — Police say they have caught up with a homeless man who allegedly threatened a teenage girl with a syringe he claimed was filled with HIV-tainted blood outside a Waltham pharmacy.

Scott Steverding was arrested overnight by Waltham investigators in Cambridge. He was arraigned Thursday on charges that include attempted murder, armed carjacking, and assault with a dangerous weapon, but did not enter a plea.

He was ordered held without bail until a dangerousness hearing.

Police say the 30-year-old Steverding threatened the 17-year-old girl on Tuesday morning, then stole her vehicle and her purse with about $200 in cash, almost striking the girl as he drove away.

Using surveillance video, police identified the suspect as Steverding. He is also a suspect in a robbery at a city gas station on Monday.

It was not immediately clear if he had a lawyer.

Copyright 2012 The Associated Press.