Some of Mr. Swartz’s defenders argue that collecting and providing evidence to the government without a warrant may have violated federal and state wiretapping statutes.

“This was a pivotal moment,” said Elliot Peters, Mr. Swartz’s lawyer. “They could have decided, we’re going to unplug this computer, take it off the network and tell the police to get a warrant.”

Mr. Peters had persuaded a judge to hear his arguments that the evidence collected from the netbook be excluded from the trial, asserting that Mr. Swartz’s Fourth Amendment protections from unlawful search and seizure had been violated. (All charges against Mr. Swartz were dropped after his death.)

Investigators first caught sight of Mr. Swartz on camera the day it was installed. At 3:26 p.m., the timeline notes, the “suspect is seen on camera entering network closet, noticeably unaware of what had occurred all morning.”

But Mr. Swartz managed to leave before the police could arrive. Also, “on his way out, the suspect shuts off the lights,” the timeline reports, which “will hurt video quality and possibly work against the motion activation of the camera.” A technician quickly turned them back on.

Mr. Swartz certainly knew his way around the M.I.T. campus — as his defense pointed out in court, he had given a guest lecture there, he had many friends on campus, and his father, Bob Swartz, remains as a consultant at the university’s Media Lab.

Two days later, the timeline notes that Aaron Swartz “enters network closet while covering his face with bike helmet, presumably thinking video cameras may be in hallway.” More seriously for the M.I.T. investigation, “once inside and with the door closed, he hurriedly removes his netbook, hard drive and network cable and stows them in his backpack.” He was gone within two minutes, too quickly for the police to catch him.