Washington, March 7 (IANS): Two days before his death, Indian American Student Dharun Ravi's roommate suspecting Ravi had spied on him began closely monitoring Ravi's Twitter account, visiting it 38 times, according to court testimony.

Just after 1 a.m. on Sep 21, 2010 Tyler Clementi opened his Sony Vaio laptop to find the first Twitter message Ravi, had written about him, Gary Charydczak, a computer expert for the Middlesex County Prosecutor's Office, told a New Jersey court Tuesday.

"Roommate asked for the room till midnight," the message read. "I went into molly's room and turned on my webcam. I saw him making out with a dude. Yay."

Eighteen hours later, at around 9:15 p.m., Clementi found another message. "Anyone with iChat, I dare you to video chat me between the hours of 9:30 and 12. Yes it's happening again," Ravi wrote.

Clementi saved screenshots of both Tweets, then continued to monitor the account until his last recorded visit, at 5:16 p.m. on Sept. 22, 2010, a computer expert who analyzed Clementi's laptop testified.

In quick succession, Clementi applied for a room change and complained to a resident assistant about the alleged invasion of privacy.

Charydczak, who analyzed Ravi's desktop computer found numerous web searches for keywords like "gay" and "homosexual."

But on cross examination, Charydczak acknowledged Ravi could have "cached" or erased from his computer any record of those searches and Twitter messages but never did, going to the defense's point that Ravi never considered what he had done a crime.

Ravi, now 20, is charged with multiple counts of bias intimidation, invasion of privacy and spying. He isn't charged in Clementi's death but if convicted on the top count of bias intimidation, faces up to 10 years in prison.