And the brutal attack was random, Snyder said. Doctors have tested the teen, who is currently in a Palm Beach County hospital, for drugs like cocaine, opiates, meth and marijuana — all of which had negative results.
The Stevens' home is in an unincorporated area of Martin County west of the village of Tequesta.
The teen took off some of his clothes during the attack, Snyder said, but did not have the raised body temperature characteristic of flakka use. When he arrived at a hospital, Harrouff was making "animal-like noises" and incoherent, Snyder said. Doctors will be testing Harrouff for bath salts and flakka. Snyder added that Moore had exhibited signs of excited delirium.
"It's inexplicable," Snyder said. "The motive is still not clear what pushed a 19-year-old Florida State student to do this."
About an hour before the killings, Harrouff was at Duffy's Sports Grill eating dinner with his parents, who told officials the teen became angry and stormed out of the restaurant on Indiantown Road at the intersection with Island Way.
He ended up about four miles away, switchblade in hand, at the Tequesta couple's house on Southeast Kokomo Lane in the Jupiter River Estates community. The sheriff's office said Stevens appeared to fight back, but Harrouff had "weapons of opportunity," meaning items around the garage, at his disposal.
He used multiple weapons to kill Mishcon and Stevens, Snyder said.
Stevens' brother-in-law, Doug Maddox, said the couple often kept their garage door up and a seat open for friends and family.
"It's just beyond me why that would happen," Maddox said outside the family's home Tuesday morning. "The guy must be crazed."
Stevens' daughter, Ivy, had moved out of the house days before, Maddox said. On Monday night deputies were looking for the 26-year-old, concerned for her safety and wanting to make sure she knew what had happened at her home. She is fine, has no connection to Harrouff and did not recognize him when shown his photo, Snyder said.
A neighbor intervened in the attack, Snyder said, but Harrouff "was abnormally strong." The neighbor was stabbed, too, and taken into surgery Monday night with "substantial trauma."