Eduardo Arevalo, 19, (pictured) was charged with murder after he allegedly confessed to killing his unwed pregnant sister because she was 'an embarrassment to their family'

A Texas teen allegedly killed his unwed pregnant sister because she was an 'embarrassment to their family' and then made her disappearance look like a suicide.

Viridiana Arevalo, a 23-year-old who was eight months pregnant, was reported missing in The Colony on December 17 by her boyfriend. Her family discovered a note in which she said she wanted to kill herself.

The mother-to-be's brother, 19-year-old Eduardo Arevalo, was arrested and charged with capital murder after her body was discovered in an alley on Sunday.

Police say Eduardo confessed to strangling Viridiana the day before she was reported missing and to writing the suicide note the family found so it would look like she took her own life.

The teen told detectives that he killed his sister because she was 'an embarrassment to their family' and 'it would be better off that she wasn't here', FOX4 reported.

Viridiana Arevalo (pictured), a 23-year-old who was eight months pregnant, was reported missing in The Colony, Texas, on December 17. Her body was discovered in an alley on Sunday

Eduardo told investigators that after he killed Viridiana, he put her body in the trunk of his car and drove half an hour away to a remote part of town, where he dumped the body.

'As the week went on, Eduardo stated that he wanted his family to know where Viri was so he went and picked up her body and brought her back Sunday morning in the early morning hours and dumped her body in the alleyway,' Sgt Aaron Woodard of The Colony Police Department said at a news conference Monday.

Neighbors soon discovered the body and contacted police.

Eduardo became a suspect after he was seen on surveillance video in the alley.

Police said Viridiana's baby was her boyfriend's child. They don't believe the boyfriend, who has not been named, or anyone else in her family was involved in her murder.

When Viridiana was first reported missing last Tuesday, authorities said there were no signs of foul play.

'We currently believe this is a voluntary absence,' Colony police tweeted on Wednesday.