WESTMINSTER, Colo. – A teen arrested in the death of a 10-year-old Colorado girl and in a separate attack on a runner was interested in mortuary science and forensic science, often wore black and hung out in the high school cafeteria’s “goth corner,” acquaintances said.

Arapahoe Community College student Austin Reed Sigg, 17, was due in court Thursday in connection with the death of Jessica Ridgeway, who lived about a mile from him. She disappeared Oct. 5 while walking to Witt Elementary School. Her remains, which authorities said weren’t intact, were found five days later.

Police in the Denver suburb of Westminster said they took Sigg into custody on Tuesday night after receiving a phone call, apparently from his mother, that led them to Sigg.