Healdsburg police arrested a Sonoma woman Tuesday afternoon who is suspected of stealing medical marijuana from a 56-year-old Healdsburg man on Friday.Melissa Ann Hirshfield, 25, was arrested at a towing company at 3615 Copperfield Drive in Santa Rosa around 1:30 p.m., Sgt. Kevin Young said.Police are still looking for two men who were also involved in the robbery, Young said. The victim knows Hirshfield and said he let two men and a woman into his home at 719 Johnson St. to look at medical marijuana. One of the three suspects ordered the victim down on the bed at gunpoint and the three suspects left the house with three zip lock bags of marijuana, police said.Young would not say whether police know the identity of the two male suspects. Hirshfield was booked into the Sonoma County jail for robbery, burglary, possession of amphetamine and possession of a syringe. Her bail is $91,000.