Arnold was featured in Lane's postings too. The father referred to her online as "peanut." A series of posts touted YouTube videos his daughter had shown him or that they had discussed, many of which had gone viral, such as the Gangnam Style video. In one post last March, Lane described pitching the idea of posting his daughter's favorite videos to his blog over lunch.

"We'll call it Peanuts Picks," he wrote, recounting the conversation. "She seemed to like that."

Last June, father and daughter went to check out a new ice cream stand in Ellicott City, according to an account Lane posted to his blog. Arnold ordered strawberry, a favorite flavor of hers, Lane wrote.

"Peanut and I took our ice cream over to a bench by the river and soaked in the summer evening while listening to the water cascading over the rocks just below us," he added. "We're heading down there again tonight."

A few months later, the name Jason Anthony Bulmer made its first appearance on Arnold's Facebook page.

"I'm very happy today," a post from Nov. 18 reads, followed by the comment, "hi Jason!"

Posts from Lane's Facebook account, which was confirmed by his lawyer, to Arnold's account appeared less frequently in recent months as his daughter wrote more and more on her own page about her affections for Bulmer.

In January, Arnold's profile picture was changed to a darkened image of a Pegasus with the words "I love Jason" printed over the top in orange text. The page is also covered with brightly colored pictures of Japanese cartoon characters and unicorns.

Their online displays of affection between Arnold and Bulmer were matched in the halls of Mount Hebron High School, according to other students at the school.

Sarah Fuss, a friend of Arnold's, said she had never really liked Bulmer, but tried to give him the benefit of the doubt for her friend's sake. "He just seemed weird to me, and a lot of other people in my classes thought the same," she said.

Residents and parents of Mount Hebron High School students said nothing seemed amiss in Lane's household, and some noticed Arnold and Bulmer were affectionate.

Rupal Shah, who lives with her family across the street from Lane's home, said he hosted Fourth of July parties and had a beautiful backyard with a gazebo, where he enjoyed entertaining neighbors. She often saw him at events such as community-association gatherings and local political fundraisers.

"I have never seen him argue with anyone," said Shah. "It is so shocking to us. ... Yesterday, I couldn't go to sleep because I was worried. Who can you trust nowadays?"

Shah's daughter, Reema, attends Mount Hebron and said she is in the same English class as Bulmer. "I would say he was a loner," Reema said of Bulmer. "Nobody ever talked to him."

Reema Shah said Morgan Arnold wore "bunny ears" to school and that she would wait for Bulmer at school.

"They were always hugging and kissing," Reema Shah said of the teen couple.