Kansas Senate candidate Milton Wolf (R) is under fire for making jokes and comments online about X-ray images of gunshot wounds and other injuries.

The Topeka Capital-Journal reported Sunday on the remarks Wolf made throughout 2010 on Facebook. Wolf, who is challenging Sen. Pat RobertsCharles (Pat) Patrick RobertsGOP senators introduce bill to prevent family separations at border Senate GOP tries to defuse Trump border crisis 13 GOP senators ask administration to pause separation of immigrant families MORE (R-Kansas) for the party’s nomination, is a radiologist and poked fun with others at the victims depicted in the images, who were either dead or wounded.

One image uploaded to Wolf’s Facebook gallery depicts the skull of a person who was shot in the head from close range, according to the doctor.

“From my residency days ... there was a pretty active 'knife and gun club' at Truman Medical Center. What kind of gun blows someone's head completely off? I gotta get me one of those,” Wolf said in a comment.

In a statement Sunday, Wolf said his comments were “insensitive” and took responsibility for them but blamed Roberts for their airing in the press.

“Several years ago, I made some comments about these images that were insensitive to the seriousness of what the images revealed. Soon thereafter, I removed those images and comments, again several years ago,” Wolf said.

“For them to be published in a much more public context now, by a political adversary who would rather declare war on doctors than answer serious questions that Kansans have, is truly sad. However, my mistakes are my own, and I take full responsibility for them.”

Wolf had already begun to ready his supporters for the press stories about his X-Ray image comments. In a statement on Saturday — just roughly three hours before the story on The Topeka Capital-Journal went online — Wolf said Roberts would launch an attack against him that would “vilify all doctors.”

“In the days ahead, an assault on my character will begin. This attack will be launched covertly through the media by my opponent out of Virginia, Pat Roberts,” Wolf said. “This assault will not only target me, but will, through its implications, cast a wider net to vilify all doctors.”

The comments could prove to be a political problem for Wolf, as he tries to oust Roberts. Wolf has been backed by conservative-leaning outside groups, but GOP establishment organizations are supporting Roberts and have attacked the challenger for the Facebook postings.

“Once again, it is clear that there are a few select groups and organizations that refuse to properly research candidates or do the necessary work prior to endorsing them, which maximizes risk and hurts the conservative cause. Time and again, it has been proven that the failure to research and vet candidates results in handing winnable seats to Democrats," said Brad Dayspring, a spokesman for the National Republican Senatorial Committee, about Wolf’s Facebook comments.

One outside group backing Wolf said on Twitter that the scrutiny of Wolf’s social media activity was a character attack on the primary challenger.

“Pat Roberts is trying to smear Dr. Wolf because Roberts doesn't live in Kansas anymore and lied to voters about it for years,” said the Senate Conservatives Fund. “The NRSC can't compete on the issues so they have to attack the character of conservatives.”