“He had emotional problems and I believe he was diagnosed with autism,” Mr. Gold said of Nikolas Cruz. “He had trouble controlling his temper. He broke things. He would do that sometimes at our house when he lost his temper. But he was always very apologetic afterwards.”

He added: “He would sometimes be hitting his head and covering his ears. One time, I sent him home because he was misbehaving at our house and he took a golf club and smashed one of my trailers.”

He said that Mr. Cruz at one point had gone to a school for students with special needs. “Kids were really picking on him and would gang up on him and beat him up a little,” Mr. Gold said. “They ostracized him. He didn’t have many friends.”…

Other neighbors said Mr. Cruz was a regular source of agitation. Helen Pasciolla said Lynda Cruz had called sheriff’s deputies to the house numerous times in an effort to keep Mr. Cruz in line. Craig Koblitz, 62, a yacht repairman who lives across the street, said some neighbors had suspected him of burglarizing a nearby house a few years ago.