A man convicted of killing his childhood mentor in New Jersey and accused of killing four more people in New Mexico has pleaded guilty in one of his cases out West. Plea agreements are in the works on the other cases, New Mexico officials confirmed Friday. Sean M. Lannon, 50, who was sentenced to 35 years in prison for the 2021 killing of Michael Dabkowski in Gloucester County, was transferred to New Mexico last year to face charges that he killed his wife and three men in that state. Lannon entered a guilty plea to a second-degree murder count on Thursday in the killing of 60-year-old Albuque…