Weapons; possession or transportation; hospital that provides mental health services or developmental services; penalty. Makes it a Class 1 misdemeanor for any person to knowingly possess in or transport into the building of any hospital that provides mental health services or developmental services in the Commonwealth, including an emergency department or other facility rendering emergency medical care, any (i) firearm or other weapon designed or intended to propel a missile or projectile of any kind; (ii) knife, except a pocket knife having a folding metal blade of less than three inches; or (iii) other dangerous weapon, including explosives and stun weapons. The bill also provides that notice of such prohibitions shall be posted conspicuously at the public entrance of any hospital and no person shall be convicted of the offense if such notice is not posted, unless such person had actual notice of the prohibitions. The bill provides that any such firearm, knife, explosive, or weapon shall be subject to seizure by a law-enforcement officer and forfeited to the Commonwealth and specifies exceptions to the prohibition. This bill is identical to SB 515.