A Topsfield man was arrested Sunday morning after allegedly assaulting two family members and then barricading himself inside his Washington Street home and making bomb and arson threats, according to Topsfield Police Chief Evan E.J. Haglund. Daniel P. Morley, 27, was charged with two counts of domestic assault and battery and one count each of threatening to commit arson and communicating a bomb scare, Haglund said. When police searched the home, he said, they found guns, knives, and a pressure cooker they feared was a bomb, though it was determined not to be an explosive. No one was injured in the standoff, which began at about 2:46 a.m. and ended when Morley was arrested around 6 a.m. Morley is scheduled to be arraigned Monday in Ipswich District Court in Newburyport, Haglund said.