The Kentucky representative posted on Twitter a picture of him and what seems to be his family in front of a Christmas tree, with all seven of them carrying guns.
"Merry Christmas!" Massie wrote on social media. "ps. Santa, please bring ammo."
The post comes only four days after a deadly shooting at a Michigan high school that ended with four dead and seven injured. Massie's post immediately ignited controversy, with some denouncing his post for being insensitive after Michigan's tragedy.
The gun used was purchased by the suspect's father days before the shooting, and the suspect's family further hired lawyers and are remaining silent.
Oakland County Sheriff Michael Bouchard said an investigation is underway yet is a "massive undertaking," due to the need of interviewing almost 1,000 witnesses, thousands of hours of surveillance footage and scanning through social media posts. No time frame for the completion of the investigation has been given.
Six students remain wounded and in the hospital from the shooting, including a teenage girl in critical condition, on a ventilator with wounds to her chest and neck. One other student is in critical condition and another is in "serious" condition. A teacher was further grazed with a bullet, though has since been discharged from the hospital.
The shooting lasted for five minutes, with 15 to 20 shots fired, according to officials.
Other users found the picture to be quite patriotic and were encouraged to take similar pictures in the future.
Democratic U.S. Representative John Yarmuth, who chairs the U.S. House of Representatives Budget Committee, condemned his fellow Kentuckian's post.
"I'm old enough to remember Republicans screaming that it was insensitive to try to protect people from gun violence after a tragedy," Yarmuth wrote on Twitter, apparently referring to calls for gun control laws.
"I promise not everyone in Kentucky is an insensitive asshole," he added.
Ethan Crumbley, the claimed shooter at Oxford High School, will be tried as an adult. James and Jennifer Crumbley's parents pleaded "not guilty" to manslaughter charges at their arraignment hearing Saturday morning.
An online petition asking the school to rename its football stadium after a shooting victim got thousands of signatures only hours after the shooting.
Jonathan van Norman, a campaign manager for Massie, did not immediately reply to a request for comment via Twitter.