Sen. John Cornyn (R-Texas) sent a letter to Attorney General Eric Holder on Friday demanding more information about the prosecution of Aaron Swartz, the co-creator of Reddit and Internet activist who killed himself last week.
Cornyn, a top Senate Republican, questioned whether the Justice Department was trying to "make an example" out of Swartz by bringing aggressive hacking charges against him.
"Mr. Swartz's case raises important questions about prosecutorial conduct," Cornyn wrote.
Swartz was an accomplished programmer and activist who argued that more online information should be free to the public.
Critics, including Swartz's family and members of Congress, have accused prosecutors of seeking excessive penalties in the case.
The charges carried a maximum penalty of 35 years in prison and a fine of up to $1 million. His trial was scheduled to begin in April.
In a statement, Swartz's family said his suicide was the "product of a criminal justice system rife with intimidation and prosecutorial overreach."
House Oversight Committee Chairman Darrell Issa (R-Calif.) plans to investigate whether prosecutors acted inappropriately in the case.
Carmen Ortiz, the U.S. attorney in charge of the case, released a statement this week defending her office's conduct, which she said was "appropriate."
"The career prosecutors handling this matter took on the difficult task of enforcing a law they had taken an oath to uphold, and did so reasonably," she said.
Ortiz acknowledged that there was no evidence indicating that Swartz sought to profit from the crime, and said her office offered him a plea deal of six months at a low-security prison.
She said that his actions, while a violation of the law, "did not warrant the severe punishments authorized by Congress."
In his letter, Cornyn demanded to know why Ortiz believes her office acted appropriately.
"Did that office, or any office with the Department, conduct a review?" Cornyn asked.
He questioned whether prosecutors gave any consideration to whether the charges and associated penalties "were proportional to Mr. Swartz's conduct and its impact upon victims."
He also asked whether the fact that the Justice Department had investigated Swartz over prior incidents led to more severe charges in this case and whether the prosecution was retaliation for Swartz filing public records requests with the agency.
Cornyn noted that Ortiz had pointed to "severe punishments authorized by Congress," and asked Holder to explain whether prosecutors have discretion to bring charges that they view as matching the gravity of the alleged wrongdoing.
Rep. Zoe Lofgren (D-Calif.) is working on legislation that would curtail the Computer Fraud and Abuse Act, the law that Swartz was accused of violating.