Back when I began researching the case of the missing Lyon Sisters, I found a Washington Post article (on microfilm) on the arrest of Raymond Rudolph "Ray" Miliski who in November 1977 murdered his wife and oldest son.
In the same section of the Post was another story about the arrest of a suspect in the abduction, rape, and murder of two nine year old boys in Maryland. That person was Ellwood Leroy Leuschner, age 45. Leuschner was eventually convicted of both murders and spent the rest of his life in prison. He had an extensive criminal record of sex crimes and crimes against children in California before he turned up in Maryland.
Although there is probably only coincidence in the fact that both Mileski and Leuschner were both caught in Maryland in the same month, and both were convicted of multiple murders, one has to wonder if there was any connection between the two - or if there was any connection with either one and all of the unsolved abductions and murders of the 1975 - 1977 timeframe.
Here is a link to Leuschner's thread in the Serial Killer section of websleuths:
MD - MD/CA - ELLWOOD LEROY LEUSCHNER serial rapist and murderer