Arizona police questioning person of interest in Phoenix serial shootings that killed 7

— -- Police in Phoenix are investigating a person of interest in connection with a series of shootings that occurred in 2016 that claimed 7 lives, a law enforcement source told ABC News.

In July, the Phoenix Police Department announced that it was searching for a gunman believed to be responding for a string of shootings, all of which occurred in the same neighborhood.

The same gunman is believed to be responsible for at least nine shooting incidents that killed seven people between March 2016 and June 2016.

The man being questioned by police is already in jail and has not yet been named a suspect, according police.

The first attack occurred on March 17, 2016, when a 16-year-old was shot while walking around 11:30 p.m. The teen survived the shooting.

The majority of the shootings followed a similar pattern.

In July, detectives released a composite sketch of the suspect with the help of a witness. The suspect had been described as a white male in his early 20s with a skinny or lanky build.

It is unclear if the victims were targeted or selected at random.

Authorities are still looking for tips from the public as they continue the investigation. The Phoenix Police Department had offered a $50,000 reward for information leading to the suspect's arrest.

“Someone out there knows who did this. We need our community to call us or Silent Witness and help us solve these cases, bring justice to these families and victims and prevent more violence from occurring,” said Phoenix Police Chief Joseph Yahner in July.

ABC News' Michael Kreisel contributed to this report.