SPRINGFIELD, Ill. — The former Illinois deputy who fatally shot Sonya Massey last month will remain jailed, a judge ruled Friday, rejecting his request to be released on bail to accommodate his medical needs, which include treatment for colon cancer.

Also Friday, Sangamon County Sheriff Jack Campbell announced he would resign, saying it had “become clear that the current political climate has made it nearly impossible” for him to continue effectively in his role.

The judge overseeing…