"[Neither] my client nor I will be making any comments. We are working and cooperating with authoritiies on this investigation," Dworski told ABC News.
Investigators tailed Clark for several days, officials said.
Police said Clark had no criminal record but his name was mentioned in a police report from Branford, Conn., in 2003, reportedly connected to an alleged sexual assault.
Clark's sister, brother-in-law and fiancee, Jennifer Hromadka, also worked in the lab building but did not go to work today.
In a blog entry last year Hromadka denied rumors that Clark was having "a fling" with a woman at work.
"He is a bit naive, doesn't always use the best judgment, definitely is not the best judge of character, but he is a good guy," Hromadka, 23, blogged.
"My boyfriend Ray, if you don't know him, has no interest in any of the other girls at [the Yale lab] as anything more than friends," she wrote.
Police cars were parked all day outside Clark's apartment complex in Middletown, Conn., about 20 miles from Yale. Neighbors said surveillance cars have been at the complex for at least 24 hours.
One of Clark's neighbors, Felicia Diaz, told ABC News she saw Clark and his fiancee leaving their apartment in a hurry the same day Annie Le's body was discovered.
"I thought it was kind of suspicious where I thought he was moving out or something because it was a lot of luggage," Diaz said. "So I really didn't know what was going on."
Clark's landlord told ABC News that she wants Clark out of the apartment complex and has served an eviction notice to his lawyer.
ABC News consultant and former FBI agent Brad Garrett said that though he had been investigated by authorities for days, it's likely police did not take Clark into custody sooner because he was not a threat to other students.
"If you do not believe they are a danger to anyone else, then you may let him go," Garrett said. "If this is a crime of passion, you're not concerned about anyone else."
Sources have previously described a suspect as being a lab technician who worked in the same building where Le studied.
Le had been seen entering the Amistad Street lab around 10 a.m. Tuesday, but none of the cameras caught her leaving. Her body was found shortly after 5 p.m. Sunday, shoved into a space in the wall meant to conceal pipes and wiring.
The medical examiner did an abrupt about face Tuesday and withheld Le's autopsy results, which would have revealed the woman's exact cause of death. The medical examiner's office said it was being withheld at the request of the New Haven state's attorney.
"One of the reasons you do not release autopsy reports is you, as the medical examiner, want to have as much information as you can before you make that report," Garrett said. "[Clark] may make statements to police, or they may find evidence that would adjust the final report."
A medical examiner positively identified the body found stuffed in a wall in a Yale University lab as the missing grad student Monday.
The body was found Sunday, the same day that the 24-year-old Le was supposed to get married.
Sources also told ABC News that bloody clothing, found behind ceiling tiles in the lab, contained evidence that linked the killer to the crime.