More than 125,000 have signed the petition, exceeding the 100,000 needed to trigger a response.
However, because Avery and Dassey were convicted in state criminal court, the president does not have the power to pardon them, the White House said.
"A pardon in this case would need to be issued at the state level by the appropriate authorities," a representative for the White House wrote online. "While this case is out of the Administration's purview, President Obama is committed to restoring the sense of fairness at the heart of our justice system."
Avery, who'd previously served 18 years in prison for a sexual assault crime that he did not commit, and Dassey, his nephew, were both sentenced to life in prison for Halbach's murder.
Avery is not eligible for parole, but Dassey will be in 2048. According to reports, Avery has appealed, but the verdict was upheld in 2011, and a local ABC affiliate in Wisconsin reported that in 2013, Dassey's request for new trial was rejected.
"Those who feel they have been wrongly convicted can seek to have their convictions overturned by a higher court," Laurel Patrick, his press secretary, told the Milwaukee Journal Sentinel earlier this week.
"Making a Murderer" has been a hit for Netflix, causing many viewers to debate whether Avery and Dassey should be behind bars.
Ken Kratz, the former Wisconsin prosecutor who handled the murder case, slammed the show for being biased and omitting key details. However, Laura Ricciardi, the show's co-writer/director, defended her work, telling the Wrap, "It was a nearly six-week-long trial, and it would just be impossible for us to include all of the less significant evidence."