Kansas City, Mo. ? A former partner in the largest Kansas-based law firm and son of a former federal appeals court judge has pleaded guilty to attempting to entice what he thought was a minor for sex.

Samuel Logan, 46, of Kansas City, Mo., will spend at least 10 years in prison after agreeing to a plea bargain announced Wednesday.

Logan, a partner with Foulston Siefkin LLP whose office was in Overland Park, Kan., admitted that he began communicating with someone he thought was a 14-year-old girl named “Stazie” last May in an Internet chatroom.

Federal prosecutors said he was in his office when he initiated the conversation and activated his webcam, allowing an agent with the Kansas attorney general’s office who was posing as the girl to watch as he performed a sexual act.

Using the screen name “sambo5604,” Logan activated a webcam 11 times while chatting with “Stazie” from June 1, 2010, to July 22, 2010, with most of the conversations being sexual in nature. During that time, Logan sent 32 pictures of pornography to the agent, including two images of child porn, prosecutors said.

He arranged to meet the girl last July 22 at a Johnson County mall and said he intended to buy a webcam for her to use in future conversations, according to the plea deal.

Prosecutors said “Stazie” introduced him to another undercover agent with the Kansas attorney general’s office who was posing as a 14-year-old girl named “Ashley.” Around that time he also began communicating with a Ulysses, Kan., officer posing as a 13-year-old girl, and with two undercover detectives with the Johnson County Sheriff’s Office posing as young girls.

Most of the conversations occurred while Logan, who identified himself to the girls as an Overland Park, Kan., lawyer named “Sam” from “KC,” was in his law office.

Logan was arrested July 22, 2010, when he went to Oak Park Mall thinking he was going to meet “Stazie,” prosecutors said.

Officers and agents saw him looking at various young girls in an effort to locate “Stazie,” and arrested him after he approached a 14-year-old he thought was the girl he was scheduled to meet, prosecutors said.

Investigators found more than 120 images of child pornography when they examined his computer and compact discs, including at least 57 images and one video that matched known child pornography listed in a database by the National Center for Missing and Exploited Children.

Logan, the son of former appellate judge James K. Logan, faces a prison sentence of at least 10 years and could get as much as life, prosecutors said. A sentencing date has not been set.